riscv: Remove unnecessary irqflags processor.h include

This include is not used and can lead to circular dependencies.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240312-fencei-v13-1-4b6bdc2bbf32@rivosinc.com


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