[PowerPC] fix stack size allocated for float point argument

This is for https://github.com/llvm/llvm-project/issues/56469

Allocate 4 bytes for float point arguments on PPC32.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D129558

GitOrigin-RevId: ef60e44fe874e28a6cfff57533b63c752a36e7dd
3 files changed