[AArch64] Remove Automatic Enablement of FEAT_F32MM (#85203)

When `+sve` is passed in the command line, if the Architecture being
targeted is V8.6A/V9.1A or later, `+f32mm` is also added. This enables
FEAT_32MM, however at the time of writing no CPU's support this. This
leads to the FEAT_32MM instructions being compiled for CPU's that do not
support them.

This commit removes the automatic enablement, however the option is
still able to be used by passing `+f32mm`.