arm: msm: add vreg reference count
arm: msm: add vreg reference count

Support independent enable and disable by clients for common
vreg. First enable switches on and last disable switches off.

This change has no check for voltage level so clients
must agree on level for common vreg.

Signed-off-by: Matthew Wilson <e3856f5992d89404de9e21455bf4297e813f390d@quicinc.com>

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