mfd: Improve mc13xxx dt binding document
mfd: Improve mc13xxx dt binding document

It improves mc13xxx dt binding document on how the regulator name
is being used for binding a mc13892 regulator device.

Signed-off-by: Shawn Guo <912cf7eb7d8018e2943586ae6657d21fd4e38239@linaro.org>
Reviewed-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <0ba86cb3f08bbb861958e54bd3438887adb4263c@linux.intel.com>

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