sparc32: fix init.c allnoconfig build error

Fix allnoconfig build error.
Signed-off-by: NRobert Reif <reif@earthlink.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/mm/init.c

@@ -22,6 +22,7 @@
 #include <linux/init.h>
 #include <linux/highmem.h>
 #include <linux/bootmem.h>
+#include <linux/pagemap.h>
 
 #include <asm/system.h>
 #include <asm/vac-ops.h>