MIPS: MSP: Fix build error

Reported and original patch by Yoichi Yuasa <yuasa@linux-mips.org>.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cevt-r4k.h

@@ -14,6 +14,9 @@
 #ifndef __ASM_CEVT_R4K_H
 #define __ASM_CEVT_R4K_H
 
+#include <linux/clockchips.h>
+#include <asm/time.h>
+
 DECLARE_PER_CPU(struct clock_event_device, mips_clockevent_device);
 
 void mips_event_handler(struct clock_event_device *dev);