tune-cortexa72: Drop the redundant cortexa72-crc tune

We have enabled the crc extension by default for cortexa72 in patch
("tune-cortexa72: Enable the crc extension by default for cortexa72"),
then the cortexa72-crc seems redundant. So drop it. We also rename the
cortexa72-crc-crypto to cortexa72-crypto. With these changes, it will
break the BSPs which used these two tunes, but it should be easy to fix.

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>