gpio: Restrict GPIO_ICH to compile testing with HAS_IOPORT

gpio: Restrict GPIO_ICH to compile testing with HAS_IOPORT

When building gpio-ich.c for a platform that does not have IO port
access like s390, there are several errors due to the use of inl() and
outl() throughout the driver:

  drivers/gpio/gpio-ich.c: In function 'ichx_read_bit':
  include/asm-generic/io.h:578:14: error: call to '_inl' declared with attribute error: inl() requires CONFIG_HAS_IOPORT

Only allow compile testing when the targeted platform selects HAS_IOPORT
so that there are no compile time errors.

Fixes: f3592d252f77 ("gpio: ich: enable building with COMPILE_TEST=y")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202504171941.g1yXja0j-lkp@intel.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250418-gpio-ich-fix-build-without-ioport-v1-1-83fc753438ec@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>