svga: add typeless switch cases in svga_typeless_format()

We sometimes pass typeless formats to this function.  By adding switch
cases we avoid the "Unexpected format XXX in svga_typeless_format"
warning messages.  No functional change.

No Piglit regressions, no above-mentioned warning messages.

Reviewed-by: Charmaine Lee <charmainel@vmware.com>
1 file changed