mfd: db8500-prcmu: Remove unused inline functions

Since commit b0e84624 ("mfd: db8500-prcmu: Remove dead code for a non-existing config")
these inline helpers also no need any more.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230720143738.13996-1-yuehaibing@huawei.com


Signed-off-by: Lee Jones <lee@kernel.org>