pinctrl: lochnagar: Don't build on MIPS

[ Upstream commit 6588732445ff19f6183f0fa72ddedf67e5a5be32 ]

MIPS appears to define a RST symbol at a high level, which clashes
with some register naming in the driver. Since there is currently
no case for running this driver on MIPS devices simply cut off the
build of this driver on MIPS.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311071303.JJMAOjy4-lkp@intel.com/


Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231115162853.1891940-1-ckeepax@opensource.cirrus.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>