[ARM] omap: fix clockdomain enable/disable ordering

Based on a patch from Paul Walmsley <paul@pwsan.com>:

 omap2_clk_enable() should enable a clock's clockdomain before
 attempting to enable its parent clock's clockdomain.  Similarly, in
 the unlikely event that the parent clock enable fails, the clockdomain
 should be disabled.

 linux-omap source commit is 6d6e285e.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-omap2/clock.c

@@ -419,20 +419,17 @@ int omap2_clk_enable(struct clk *clk)
 	int ret = 0;
 
 	if (clk->usecount++ == 0) {
+		if (clk->clkdm)
+			omap2_clkdm_clk_enable(clk->clkdm, clk);
+
 		if (clk->parent) {
 			ret = omap2_clk_enable(clk->parent);
 			if (ret)
 				goto err;
 		}
 
-		if (clk->clkdm)
-			omap2_clkdm_clk_enable(clk->clkdm, clk);
-
 		ret = _omap2_clk_enable(clk);
 		if (ret) {
-			if (clk->clkdm)
-				omap2_clkdm_clk_disable(clk->clkdm, clk);
-
 			if (clk->parent)
 				omap2_clk_disable(clk->parent);
 
@@ -442,6 +439,8 @@ int omap2_clk_enable(struct clk *clk)
 	return ret;
 
 err:
+	if (clk->clkdm)
+		omap2_clkdm_clk_disable(clk->clkdm, clk);
 	clk->usecount--;
 	return ret;
 }