platform: starfive: remove redundant compatibility check in pmic_ops

pmic_ops() is only called if a compatible device is found in device
tree. It is redundant for this function to check the compability again.
Remove this check.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Tested-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>