[CPU] Fix u8 -> bool conversion in cpu_convert.cpp (#32919)
### Details:
u8 -> bool conversion after merging
https://github.com/openvinotoolkit/openvino/pull/32389 produces 127 in
case of true in some cases (instead of 1)
Enable `smoke_IsOp*` tests on RISC-V platform that are affected by this
comparison issue
### Tickets:
- 176707
