Avoid the array lookup, converting the PLL macros after ICL to
_PICK_EVEN_RANGES. This provides the following reduction in code size:

	$ size build64/drivers/gpu/drm/i915/i915.o{.old,.new}
	   text    data     bss     dec     hex filename
	4027456  185703    6984 4220143  4064ef build64/drivers/gpu/drm/i915/i915.o.old
	4026997  185703    6984 4219684  406324 build64/drivers/gpu/drm/i915/i915.o.new

At the same time it's safer, avoiding out-of-bounds array access.  This
allows to remove _MMIO_PLL3() that is now unused.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230120193457.3295977-4-lucas.demarchi@intel.com