soc: fsl: qbman: Add helper for sanity checking cgr ops

[ Upstream commit d0e17a4653cebc2c8a20251c837dd1fcec5014d9 ]

This breaks out/combines get_affine_portal and the cgr sanity check in
preparation for the next commit. No functional change intended.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: fbec4e7fed89 ("soc: fsl: qbman: Use raw spinlock for cgr_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>