mfd: Fix a few spelling mistakes in PMIC header file comments

Fix four comment typos in MFD PMIC header files.

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Kaihua Zhong <zhongkaihua@kylinos.cn>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20231129015526.3302865-1-zhongkaihua@kylinos.cn


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