clk: wrap I/O access for improved portability

the common clock drivers were motivated/initiated by ARM development
and apparently assume little endian peripherals

wrap register/peripherals access in the common code (div, gate, mux)
in preparation of adding COMMON_CLK support for other platforms

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 0811633..4f96ff3 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -42,7 +42,7 @@
 	 * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
 	 * val = 0x4 really means "bit 2, index starts at bit 0"
 	 */
-	val = readl(mux->reg) >> mux->shift;
+	val = clk_readl(mux->reg) >> mux->shift;
 	val &= mux->mask;
 
 	if (mux->table) {
@@ -89,11 +89,11 @@
 	if (mux->flags & CLK_MUX_HIWORD_MASK) {
 		val = mux->mask << (mux->shift + 16);
 	} else {
-		val = readl(mux->reg);
+		val = clk_readl(mux->reg);
 		val &= ~(mux->mask << mux->shift);
 	}
 	val |= index << mux->shift;
-	writel(val, mux->reg);
+	clk_writel(val, mux->reg);
 
 	if (mux->lock)
 		spin_unlock_irqrestore(mux->lock, flags);