[cpu] fix Sigmoid f32 implementation on non-amd64 platform (#24749)
### Description
Fixes operator `Sigmoid` f32 implementation on non-amd64 platform.
Issue #23943 reports output data may be out of range [0, 1].
Tasks:
- [x] Verify the change fixes issue #23943
- [ ] Perform MLAS performance testing to ensure no (or acceptable)
regression.