Keyboard: Rename alt67 to alt (#3824)

Renamed keyboard alt67 to alt and adjusted necessary files where alt67 appeared.
CTRL keymap fixed enum structure name.
usb2422 removed stray define no longer used.

keyboards/massdrop/alt/config.h

@@ -25,7 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define DEVICE_VER          0x0101
 
 #define MANUFACTURER        "Massdrop Inc."
-#define PRODUCT             "ALT67 Keyboard"
+#define PRODUCT             "ALT Keyboard"
 #define SERIAL_NUM          "Unavailable"
 
 /* key matrix size */

keyboards/massdrop/alt/keymaps/default/keymap.c

@@ -1,6 +1,6 @@
 #include QMK_KEYBOARD_H
 
-enum alt67_keycodes {
+enum alt_keycodes {
     L_BRI = SAFE_RANGE, //LED Brightness Increase
     L_BRD,              //LED Brightness Decrease
     L_PTN,              //LED Pattern Select Next

keyboards/massdrop/alt/led_programs.c

@@ -15,7 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "alt67.h"
+#include "alt.h"
 #include "led_matrix.h"
 
 //Teal <-> Salmon

keyboards/massdrop/alt/matrix.c

@@ -15,7 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "alt67.h"
+#include "alt.h"
 
 #include "d51_util.h"
 #include "debug.h"

keyboards/massdrop/alt/readme.md

@@ -5,16 +5,16 @@
 The Massdrop ALT is a 65% mechanical keyboard featuring dual USB-C connectors, an integrated Hi-Speed USB 2.0 hub, and fully customizable RGB backlighting and underlighting.
 
 Keyboard Maintainer: [Massdrop](https://github.com/massdrop)  
-Hardware Supported: Massdrop, Inc. ALT67 PCBs utilizing Microchip's ATSAMD51J18A MCU and USB2422 2-Port USB 2.0 Hi-Speed Hub Controller, and ISSI's IS31FL3733 LED Drivers.  
+Hardware Supported: Massdrop, Inc. ALT PCBs utilizing Microchip's ATSAMD51J18A MCU and USB2422 2-Port USB 2.0 Hi-Speed Hub Controller, and ISSI's IS31FL3733 LED Drivers.  
 Hardware Availability: [Massdrop ALT Mechanical Keyboard](https://www.massdrop.com/buy/massdrop-alt-mechanical-keyboard)
 
 Make example for this keyboard (after setting up your build environment):
 
-    make massdrop/alt67:default
+    make massdrop/alt:default
 
 For information on flashing this keyboard, visit the following links:
 
 [Massdrop Loader Releases](https://github.com/Massdrop/mdloader/releases/tag/0.0.1)  
 [Massdrop Loader Repository and Instructions](https://github.com/Massdrop/mdloader)
 
-See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).

keyboards/massdrop/ctrl/keymaps/default/keymap.c

@@ -1,6 +1,6 @@
 #include QMK_KEYBOARD_H
 
-enum alt67_keycodes {
+enum ctrl_keycodes {
     L_BRI = SAFE_RANGE, //LED Brightness Increase
     L_BRD,              //LED Brightness Decrease
     L_PTN,              //LED Pattern Select Next

tmk_core/protocol/arm_atsam/usb/usb2422.h

@@ -18,7 +18,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef _USB2422_H_
 #define _USB2422_H_
 
-#define USB2422_ALT67_1P0
 #define REV_USB2422        0x100
 
 #define USB2422_ADDR       0x58 //I2C device address, one instance