riscv: alternatives: Don't name unused macro parameters

Without CONFIG_RISCV_ALTERNATIVE only the first parameter of the
ALTERNATIVE macros is needed. Use ... for the rest to cut down on
clutter. While there, fix a couple space vs. tab issues.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221129150053.50464-3-ajones@ventanamicro.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>