drm/i915: Rename ivb_load_lut_10_max

This patch renames function ivb_load_lut_10_max to
ivb_load_lut_ext_max.

V3: Added Vill'es r-b.

Cc: Uma Shankar <uma.shankar@intel.com>

Suggested-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1560321900-18318-4-git-send-email-uma.shankar@intel.com