spi: xtensa-xtfpga: fix register endianness
spi: xtensa-xtfpga: fix register endianness

XTFPGA SPI controller has native endian registers.
Fix register acessors so that they work in big-endian configurations.

Signed-off-by: Max Filippov <8c5ea195856807f4f02a6e0749c87ea6b7375f38@gmail.com>
Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@kernel.org>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs