meson: Add coroutines component to llvmpipe build.

Fixes: d32690b43c ("gallivm: add coroutine pass manager support")
Suggested-by: Gert Wollny <gert.wollny@collabora.com>
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>

meson.build

@@ -1254,6 +1254,8 @@ if with_gallium_opencl
     'all-targets', 'linker', 'coverage', 'instrumentation', 'ipo', 'irreader',
     'lto', 'option', 'objcarcopts', 'profiledata',
   ]
+endif
+if with_gallium_opencl or with_gallium_softpipe
   llvm_optional_modules += ['coroutines']
 endif