mfd: Guard max77686_pmic_dt_match with CONFIG_OF
mfd: Guard max77686_pmic_dt_match with CONFIG_OF

This fixes below build warning if CONFIG_OF is not set.

  CC      drivers/mfd/max77686.o
drivers/mfd/max77686.c:37:42: warning: 'max77686_pmic_dt_match' defined but not used [-Wunused-variable]

Signed-off-by: Axel Lin <b6ffd6973e972cb999e8e535ab74da7fee0c035f@gmail.com>
Signed-off-by: Samuel Ortiz <0ba86cb3f08bbb861958e54bd3438887adb4263c@linux.intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas