[AArch64] Ampere1 does not support MTE

The initial support for the Ampere1 mistakenly signalled support for
the MTE feature.  However, the core does not include the optional MTE
functionality.

Update the target parser to not include MTE for Ampere1.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D125191

(cherry picked from commit 91b24b01)