mfd: sm501: Fix mismatches of request_mem_region

This driver misuses release_resource + kfree to match request_mem_region,
which is incorrect.
The right way is to use release_mem_region.
Replace the mismatched calls with the right ones to fix it.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>