m32r: export __ndelay

ERROR: "__ndelay" [drivers/spi/spi_bitbang.ko] undefined!

Reported-by: Adrian Bunk <[e-mail]>
Signed-off-by: Adrian Bunk <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Hirokazu Takata <[e-mail]>

arch/m32r/lib/delay.c

···
  */
 
 #include <linux/param.h>
+#include <linux/module.h>
 #ifdef CONFIG_SMP
 #include <linux/sched.h>
 #include <asm/current.h>
···
 {
 	__const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
 }
+EXPORT_SYMBOL(__ndelay);