m32r: export __ndelay

ERROR: "__ndelay" [drivers/spi/spi_bitbang.ko] undefined!
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

arch/m32r/lib/delay.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/param.h>
+#include <linux/module.h>
 #ifdef CONFIG_SMP
 #include <linux/sched.h>
 #include <asm/current.h>
@@ -121,3 +122,4 @@ void __ndelay(unsigned long nsecs)
 {
 	__const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */
 }
+EXPORT_SYMBOL(__ndelay);