drm/i915/dram: Don't call skl_get_dram_info()/skl_get_dram_type() on icl

drm/i915/dram: Don't call skl_get_dram_info()/skl_get_dram_type() on icl

Currently the icl codepaths first determine the memory type from the
memory controller registers (via skl_get_dram_info()->skl_get_dram_type())
and then overwrite the results with icl_pcode_read_mem_global_info().
Get rid of the pointless (and potentially incorrect) skl_get_dram_type()
stuff.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250902133113.18778-8-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>