llvmpipe: fix txq for 1d/2d arrays. (v3)

llvmpipe: fix txq for 1d/2d arrays. (v3)

Noticed would fail, we were doing two things wrong

a) 1d arrays require the layers in height
b) minifying the layers field.

v2: don't change height code, fixup completely inside txq
as suggested by Roland.

v3: just add minify before texture array size

v1: Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>