pinctrl: ingenic: Garbage-collect code paths for SoCs disabled by config

By being a bit smarter about how the SoC version checks are performed,
it is possible to have all the code paths that correspond to SoCs
disabled in the kernel config automatically marked as dead code by the
compiler, and therefore garbage-collected.

With this patch, when compiling a kernel that only targets the JZ4760
for instance, the driver is now about 4.5 KiB smaller.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220412162218.32509-1-paul@crapouillou.netSigned-off-by: Linus Walleij <linus.walleij@linaro.org>