drm/amd/powerplay: rv: Use designated initializers

As done for vega10 in commit 3ddd396f ("drm/amd/powerplay: Use
designated initializers") mark other tableFunction entries with designated
initializers. The randstruct plugin requires designated initializers for
structures that are entirely function pointers.

Cc: Rex Zhu <Rex.Zhu@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>