mfd: 88pm860x-i2c: Repair 'space before tab' warning

Fixes checkpatch warning:

    WARNING: please, no space before tabs
    #5: FILE: drivers/mfd/88pm860x-i2c.c:5:
    + * ^IHaojian Zhuang <haojian.zhuang@marvell.com>$

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