When we generate an input signature for a vertex shader, we should
use the transpose of the matrix type instead of the matrix type
itself. This was breaking dEQP tests 'shaders.functions.datatypes'.

BUG=angle:594

Change-Id: Ia945ffd865d7255500f7a62394bcd5bdfbbedef4
Reviewed-on: https://chromium-review.googlesource.com/191461Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>