drivers: display: st7789v: Remove explicit cast
drivers: display: st7789v: Remove explicit cast

Remove explicit cast of `data`.

Signed-off-by: Casper Meijn <ef7830db5bfbf3536820c00105ab5734ef4609fc@meijn.net>

finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr