meson: Version libMesaOpenCL like autotools does

This is for parity with autotools. It names the library
libMesaOpenCL.so.1.0.0 and points mesa.icd to the .1 symlink.

opencl_version now matches configure.ac's OPENCL_VERSION.

Signed-off-by: Jan Alexander Steffens (heftig) <jan.steffens@gmail.com>
Tested-By: Aaron Watry <awatry@gmail.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>

src/gallium/targets/opencl/meson.build

@@ -20,7 +20,7 @@
 
 opencl_link_args = []
 opencl_link_deps = []
-opencl_version = '1.0'
+opencl_version = '1'
 
 if with_ld_version_script
   opencl_link_args += [
@@ -55,7 +55,7 @@ libopencl = shared_library(
     cpp.find_library('clangLex', dirs : llvm_libdir),
     cpp.find_library('clangBasic', dirs : llvm_libdir),
   ],
-  version : opencl_version,
+  version : '@0@.0.0'.format(opencl_version),
   install : true,
 )