MIPS: MSP71xx: Remove compilation error when CONFIG_MIPS_MT is present
When CONFIG_MIPS_MT is defined, code is enabled that tries to call
'set_vi_handler()'. This function is declared in <asm/setup.h> but the
header is never included. Therefore, the compilation breaks.
arch/mips/pmcs-msp71xx/msp_irq.c:133: error: implicit declaration of function 'set_vi_handler'