Revert "CPUBlas: Use opmath_type for alpha/beta scalars (#65839)"
This reverts commit 7705175f8378a769232aa6b1dde38e70ab749be9.
Reverted https://github.com/pytorch/pytorch/pull/65839 on behalf of https://github.com/malfet due to Caused significant perf regression, see https://github.com/pytorch/benchmark/issues/1016
