sparc32: fix sparse warnings in srmmu.c

Fix following warnings:
srmmu.c:78:5: warning: symbol 'flush_page_for_dma_global' was not declared. Should it be static?
srmmu.c:85:5: warning: symbol 'viking_mxcc_present' was not declared. Should it be static?
srmmu.c:103:6: warning: symbol 'srmmu_nocache_bitmap' was not declared. Should it be static?
srmmu.c:176:24: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:870:13: warning: symbol 'srmmu_paging_init' was not declared. Should it be static?

Add proper prototypes in mm_32.h and drop local prototype in init_32.c
Replace 0 with NULL

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
index 28f96f2..35384cb 100644
--- a/arch/sparc/mm/iommu.c
+++ b/arch/sparc/mm/iommu.c
@@ -27,6 +27,8 @@
 #include <asm/iommu.h>
 #include <asm/dma.h>
 
+#include "mm_32.h"
+
 /*
  * This can be sized dynamically, but we will do this
  * only when we have a guidance about actual I/O pressures.
@@ -37,9 +39,6 @@
 #define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
 #define IOMMU_ORDER	6				/* 4096 * (1<<6) */
 
-/* srmmu.c */
-extern int viking_mxcc_present;
-extern int flush_page_for_dma_global;
 static int viking_flush;
 /* viking.S */
 extern void viking_flush_page(unsigned long page);