clk: mvebu: Mark ioremapped memory as __iomem

Silence the following sparse warning

drivers/clk/mvebu/dove-divider.c:252:14: warning: incorrect type in assignment (different address spaces)
drivers/clk/mvebu/dove-divider.c:252:14:    expected void *base
drivers/clk/mvebu/dove-divider.c:252:14:    got void [noderef] <asn:2>*
drivers/clk/mvebu/dove-divider.c:256:13: warning: incorrect type in argument 2 (different address spaces)
drivers/clk/mvebu/dove-divider.c:256:13:    expected void [noderef] <asn:2>*base
drivers/clk/mvebu/dove-divider.c:256:13:    got void *base
drivers/clk/mvebu/dove-divider.c:257:25: warning: incorrect type in argument 1 (different address spaces)
drivers/clk/mvebu/dove-divider.c:257:25:    expected void volatile [noderef] <asn:2>*iomem_cookie
drivers/clk/mvebu/dove-divider.c:257:25:    got void *base

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/mvebu/dove-divider.c

@@ -247,7 +247,7 @@ static struct clk_onecell_data dove_divider_data = {
 
 void __init dove_divider_clk_init(struct device_node *np)
 {
-	void *base;
+	void __iomem *base;
 
 	base = of_iomap(np, 0);
 	if (WARN_ON(!base))