staging: hikey9xx: fix warning styling issues

Fix "WARNING: please, no space before tabs" styling issue in
hi6421-spmi-pmic.c for lines 51,52,53 and 69.
Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>
Link: https://lore.kernel.org/r/20210219101812.3483-1-alaaemadhossney.ae@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>