riscv: dts: starfive: Enable SDIO wifi on JH7100 boards

Add pinctrl and MMC controller nodes for the Broadcom wifi controller
on the BeagleV Starlight and StarFive VisionFive V1 boards.

Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>