Clean up AES-CTR VAES macros

Some macros in the VAES implementation of AES-CTR were
not using some registers, but they were still being passed.
This commit reduces the number of registers passed
and also sort the names of some ZMM registers, so
they are consecutive.

Change-Id: Id636603ec5bf58e38b2b2b6a4deb0af7deb925e0