radv: copy the user SGPRs locations outside of radv_declare_shader_args()

radv: copy the user SGPRs locations outside of radv_declare_shader_args()

The shader locations are now directly stored in radv_shader_args which
makes sense because they are tied to the arguments. The locations are
then copied to radv_shader_info but they will be moved into a new
radv_shader_binary_info with upcoming changes.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13542>