usb: musb: drop musb_platform_save/restore_context

... that can be easily folded into the
musb_platform_suspend/resume calls.

Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --cc drivers/usb/musb/am35x.c
Simple merge

diff --cc drivers/usb/musb/blackfin.c
Simple merge

diff --cc drivers/usb/musb/musb_core.c
Simple merge

diff --cc drivers/usb/musb/musb_core.h
Simple merge

diff --cc drivers/usb/musb/omap2430.c
Simple merge