intel: Fix requests for exact surface row pitch (v2)

intel: Fix requests for exact surface row pitch (v2)

All callers of isl_surf_init() that set 'min_row_pitch' wanted to
request an *exact* row pitch, as evidenced by nearby asserts, but isl
lacked API for doing so. Now that isl has an API for that, update the
code to use it.

v2: Assert that isl_surf_init() succeeds because the callers assume
    it.  [for jekstrand]

Reviewed-by: Nanley Chery <nanley.g.chery@intel.com> (v1)
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com> (v1)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> (v2)