intel/blorp/copy: Properly handle clear colors for CCS_E images

intel/blorp/copy: Properly handle clear colors for CCS_E images

In order to handle CCS_E, we stomp the image format to a UINT format and
then do some bitcasting logic in the shader.  This works fine since SKL
render compression only considers the channel layout of the format and
not the format itself.  In order for this to work on images that have
been fast-cleared, we need to also convert the clear color so that, when
interpreted as UINT, it provides the same bit value as it would have in
the original format.  This fixes a bunch of OpenGL ES CTS tests for
copy_image when we start using CCS more aggressively.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Cc: "17.0" <mesa-stable@lists.freedesktop.org>