anv/iris: use slow clear for small surfaces with Wa_18020603990
Described in Wa_18020603990, we need to use slow clear or add an
partial resolve after fast clear for surfaces where bpp <= 32 and
dim <= 256x256.Edited by Tapani Pälli
Described in Wa_18020603990, we need to use slow clear or add an
partial resolve after fast clear for surfaces where bpp <= 32 and
dim <= 256x256.