sunxi: Clean up inclusions of asm/arch/gpio.h

sunxi: Clean up inclusions of asm/arch/gpio.h

As part of migrating to DM_GPIO and DM_PINCTRL, eventually we will
remove the asm/arch/gpio.h header. In preparation, clean up the various
files that include it.

Some files did not contain any GPIO code at all, so this header was
completely unused.

A few files contained only legacy platform-specific GPIO code for
setting up pin muxes. They were left unchanged, as that code will be
completely removed by the DM_PINCTRL migration.

The remaining files contain some combination of DM_GPIO and legacy GPIO
code. For those, switch to including asm/gpio.h (if it wasn't included
already). Right now, this header provides both sets of functions,
because ARCH_SUNXI selects GPIO_EXTRA_HEADER. This will still be the
right header to include once the DM_GPIO migration is complete and
GPIO_EXTRA_HEADER is no longer needed.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>