Adding NxM matrices uniform support

Added NxM matrices related functions
and entries to Program and utilities.

Change-Id: I5839c21cb3a9dc469fca4c553a0b5f97e0ad48bf
Reviewed-on: https://swiftshader-review.googlesource.com/3105
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>