drm/i915: Convert PIPE3/PORT3 to _PICK_EVEN_2RANGES()

Like done for when __var_args__ were used, but size-wise it's also
benefitial to avoid _PICK() used for 3 ports/pipes:

	$ size build64/drivers/gpu/drm/i915/i915.o{.old,.new}
	   text    data     bss     dec     hex filename
	4026288  185703    6984 4218975  40605f build64/drivers/gpu/drm/i915/i915.o.old
	4025496  185703    6984 4218183  405d47 build64/drivers/gpu/drm/i915/i915.o.new

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/20230120193457.3295977-6-lucas.demarchi@intel.com