usb: musb: use io{read,write}*_rep accessors

The {read,write}s{b,w,l} operations are not defined by all architectures
and are being removed from the asm-generic/io.h interface.

This patch replaces the usage of these string functions in the musb
accessors with io{read,write}{8,16,32}_rep calls instead.

Signed-off-by: Matthew Leach <matthew@mattleach.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>