isl: Fix assert on raw buffer surface state size
isl: Fix assert on raw buffer surface state size

See inline PRM reference.

Cc: 12.0 <59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org>
Signed-off-by: Nanley Chery <d78cd5d33e98a5581566f188959f731bd0b1c0fd@intel.com>
Reviewed-by: Jason Ekstrand <68c46a606457643eab92053c1c05574abb26f861@jlekstrand.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler