MIPS: MSP71xx: Fix typo in msp_per_irq_controller

MIPS: MSP71xx: Fix typo in msp_per_irq_controller

  CC      arch/mips/pmc-sierra/msp71xx/msp_irq_per.o
arch/mips/pmc-sierra/msp71xx/msp_irq_per.c:101:2: error: expected identifier before '.' token
make[2]: *** [arch/mips/pmc-sierra/msp71xx/msp_irq_per.o] Error 1

Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2246/
Cc: linux-mips <linux-mips@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>