[MYON2][CONXM] add support for ATM 7" LVDS
- TOUCH_INT and TOUCH_RESET removed from myon2-pinfunc.h because they may change
- legacy-drivers for backlight and lvds-bridge are no longer available
- pinctrl for touch added
- reserved@board section removed
- hog-gpios for pwm and backlight removed, this is done by the drivers
- more generic name for the hdmi bridge