riscv: errata: Fix the PAUSE Opcode for MIPS P8700

riscv: errata: Fix the PAUSE Opcode for MIPS P8700

Add ERRATA_MIPS and ERRATA_MIPS_P8700_PAUSE_OPCODE configs.
Handle errata for the MIPS PAUSE instruction.

Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com>
Signed-off-by: Aleksandar Rikalo <arikalo@gmail.com>
Signed-off-by: Raj Vishwanathan4 <rvishwanathan@mips.com>
Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250724-p8700-pause-v5-7-a6cbbe1c3412@htecgroup.com
[pjw@kernel.org: updated to apply and compile; fixed a checkpatch issue]
Signed-off-by: Paul Walmsley <pjw@kernel.org>