Sparce doesn't seem to like using be32_to_cpu and cpu_to_be32 to convert
values for the MMIO gmux to/from the host architecture.

Instead use iowrite32be and ioread32be to always convert, which should be
fine because apple-gmux is only used on x86 with is always little endian.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305161712.5l3f4iI4-lkp@intel.com/Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
Link: https://lore.kernel.org/r/20230614064931.3263-2-orlandoch.dev@gmail.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>