sparc32: fix sparse warnings in ioport.c

Fix following warnings:
ioport.c:189:38: warning: Using plain integer as NULL pointer
ioport.c:78:25: warning: symbol 'sparc_iomap' was not declared. Should it be static?
ioport.c:403:20: warning: symbol 'sbus_dma_ops' was not declared. Should it be static?
ioport.c:684:39: warning: Using plain integer as NULL pointer

Add one missing prototype, and use NULL.
sbus_dma_ops declared static.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/pgalloc_32.h

@@ -14,6 +14,8 @@ struct page;
 void *srmmu_get_nocache(int size, int align);
 void srmmu_free_nocache(void *addr, int size);
 
+extern struct resource sparc_iomap;
+
 #define check_pgt_cache()	do { } while (0)
 
 pgd_t *get_pgd_fast(void);

arch/sparc/kernel/ioport.c

@@ -186,7 +186,7 @@ static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
 
 	if (name == NULL) name = "???";
 
-	if ((xres = xres_alloc()) != 0) {
+	if ((xres = xres_alloc()) != NULL) {
 		tack = xres->xname;
 		res = &xres->xres;
 	} else {
@@ -400,7 +400,7 @@ static void sbus_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 	BUG();
 }
 
-struct dma_map_ops sbus_dma_ops = {
+static struct dma_map_ops sbus_dma_ops = {
 	.alloc			= sbus_alloc_coherent,
 	.free			= sbus_free_coherent,
 	.map_page		= sbus_map_page,
@@ -681,7 +681,7 @@ static int sparc_io_proc_show(struct seq_file *m, void *v)
 	const char *nm;
 
 	for (r = root->child; r != NULL; r = r->sibling) {
-		if ((nm = r->name) == 0) nm = "???";
+		if ((nm = r->name) == NULL) nm = "???";
 		seq_printf(m, "%016llx-%016llx: %s\n",
 				(unsigned long long)r->start,
 				(unsigned long long)r->end, nm);