* model01: implement RGB matrix feature
LEDs can still be individually controlled if this is switched off.
* model01: use fast banked LED setting commands
* model01: update default keymap to use RGB matrix
* model01: update RGB matrix support to match common_features.mk
* rgb_matrix: include <string.h>
This was missing after commit 4d5705ea6c
which introduces a use of memset().
* model01: make g_rgb_leds weak
This allows users to override which LEDs are configured as
modifiers, or tweak the x/y coordinates, should they so choose.