riscv: dts: starfive: jh7110-common: use macros for MMC0 pins

riscv: dts: starfive: jh7110-common: use macros for MMC0 pins

The pin names of MMC0 pinmux is defined in the pinctrl dt binding header
associated with starfive,jh7110-pinctrl .

Include the header file and use these names instead of raw numbers for
defining MMC0 pinmux.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>