target-arm: Fix some copy-and-paste errors in cp register names

target-arm: Fix some copy-and-paste errors in cp register names

Fix a couple of cases where cp register names were copy-and-pasted.
These are harmless since we don't use the name for anything (except
debugging convenience) but could be confusing.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Igor Mitsyanko <i.mitsyanko@samsung.com>