drm: ast: fix double __iomem sparse warning

sparse complains about having 2 "__iomem" attributes on the same line
where only one is needed since the first one applies to everything
up to the ending ';'.
However, to make it clear(er) that both of these pointers are
"__iomem", use separate lines for them.

../drivers/gpu/drm/ast/ast_cursor.c:256:26: CK: warning: duplicate [noderef]
../drivers/gpu/drm/ast/ast_cursor.c:256:26: CK: error: multiple address space given: __iomem & __iomem

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Dave Airlie <airlied@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org

drivers/gpu/drm/ast/ast_cursor.c

@@ -253,7 +253,8 @@ void ast_cursor_show(struct ast_private *ast, int x, int y,
 		     unsigned int offset_x, unsigned int offset_y)
 {
 	u8 x_offset, y_offset;
-	u8 __iomem *dst, __iomem *sig;
+	u8 __iomem *dst;
+	u8 __iomem *sig;
 	u8 jreg;
 
 	dst = ast->cursor.vaddr[ast->cursor.next_index];