clover: Update OpenCL version string to match OpenGL

clover: Update OpenCL version string to match OpenGL

Change MESA into Mesa in CL_PLATFORM_VERSION and CL_DEVICE_VERSION. For
both, always append git version suffix from git_sha1.h.

v5: move semicolon to same line as MESA_GIT_SHA1.
v4: drop #ifdef guards.
v3: add missing include.
v2: change CL_DEVICE_VERSION as well.

Cc: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
(cherry picked from commit 4825264f75c83576f251290547f121f066b46a70)

Squashed with commit

clover: Include generated sources in AM_CPPFLAGS

git_sha1.c is generated in $(top_builddir)/src.

Fixes out-of-tree builds since 4825264f75c83576.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96516
Signed-off-by: Aaron Watry <awatry@gmail.com>
Reviewed-and-Tested-by: Michel Dänzer <michel.daenzer@amd.com>
(cherry picked from commit fafe026dbe0680c971bf3ba2452954eea84287f2)