anv/blorp: Rework image clear/resolve helpers

anv/blorp: Rework image clear/resolve helpers

This replaces image_fast_clear and ccs_resolve with two new helpers that
simply perform an isl_aux_op whatever that may be on CCS or MCS.  This
is a bit cleaner as it separates performing the aux operation from which
blorp helper we have to call to do it.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>