Option missing from riscvstep in pipeline-riscv.c

[btsouts]

Describe the bug
In pipeline-riscv.c in function riscvstep the switch (S->riscv->P.EX.format) case is missing an option which exists in riscvfaststep. Assign @btsouts.

[phillipstanleymarbell]

This is now fixed. @btsouts please tag with the corresponding issue / commit that addressed this.