Move branch comparisons to ALU

[openhwgroup]

Move branch comparisons to ALU

[raulbehl]

I have made the required changes and opened the #15 pull request.
I was not able to verify whether the changes would lead to area savings as suggested in the bug description but I have verified the changes functionally. I have run the following tests with the changes in place:
rv64ui-p-beq, rv64ui-v-beq
rv64ui-p-bne, rv64ui-v-bne
rv64ui-p-bge, rv64ui-v-bge
rv64ui-p-bgeu, rv64ui-v-bgeu
rv64ui-p-blt, rv64ui-v-blt
rv64ui-p-bltu, rv64ui-v-bltu

I did not see any fails with the above tests. Let me know if more validation is needed.

Thank you!

[zarubaf]

Again, really appreciate the contribution! Thanks a lot!

[raulbehl]

Thanks for the merge. Happy to contribute.