pinctrl: imx1: Fix too generic defines

The "PC" define is colliding with the (apparently broadcased)
define for "program counter" on Loongarch, so let's rename all
these 2-letter defines so they don't collide with stuff.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410020940.wGISlWfV-lkp@intel.com/


Fixes: a55222b7 ("pinctrl: freescale: enable use with COMPILE_TEST")
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>