i965/blorp: Do not skip fast color clear with new color

i965/blorp: Do not skip fast color clear with new color

This hasn't been visible before. It showed up with lossless
compression with:

dEQP-GLES3.functional.fbo.color.repeated_clear.sample.tex2d.rgb8

Current fast clear logic kicks color resolves even for gpu sampling.
In the test case this results into trashing of the fast color clear
state between two subsequent clears, and therefore each clear is
performed correctly.
With lossless compression the resolves are unnecessary and therefore
the clear state indicates that the buffer is already cleared. Without
considering if the previous color value was the same as the new,
clears that need to be performed are skipped and the buffer ends up
holding old pixel values.

v2 (Ken): Fix the comparison for gen < 9

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>