drm/i915/hdcp: move i915 specific HDCP GSC implementation to i915
The HDCP GSC implementation is different for both i915 and xe. Move the
i915 specific implementation from display to i915 core.
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/d362b256934c6c739d9decda717df2dbc3752481.1764090990.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>