regmap: mmio: Support accelerared noinc operations

Use the newly added callback for accelerated noinc MMIO
to provide writesb, writesw, writesl, writesq, readsb, readsw,
readsl and readsq.

A special quirk is needed to deal with big endian regmaps: there
are no accelerated operations defined for big endian, so fall
back to calling the big endian operations itereatively for this
case.

The Hexagon architecture turns out to have an incomplete
<asm/io.h>: writesb() is not implemented. Fix this by doing
what other architectures do: include <asm-generic/io.h> into
the <asm/io.h> file.

Cc: Brian Cain <bcain@quicinc.com>
Cc: linux-hexagon@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220816204832.265837-2-linus.walleij@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>