usb: musb: read MUSB_POWER register only when required.
usb: musb: read MUSB_POWER register only when required.

This is part of the workaround for AM35x advisory Advisory 1.1.20.
The advisory says that the IPSS bridge can't handle 8 & 16 bit read
access. An 8bit read access to MUSB_POWER results in an 32bit read
access which also reads INTRTX and therefore may lose interrupts.
This patch tries to minimize reads to MUSB_POWER and perform them only
when required.

Signed-off-by: Sebastian Andrzej Siewior <265264fed90bdf8e813a354375ec16f47ebdb1c5@linutronix.de>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

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