msm: msm_xo: Migrate to new clock APIs

Use the clk_prepare and clk_unprepare APIs to conform with the
changes to the clock APIs.

Change-Id: I3771ab992efcf83838d769776249379d9505ba28
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/arch/arm/mach-msm/msm_xo.c b/arch/arm/mach-msm/msm_xo.c
index 8254502..2d61504 100644
--- a/arch/arm/mach-msm/msm_xo.c
+++ b/arch/arm/mach-msm/msm_xo.c
@@ -259,9 +259,9 @@
 		}
 		/* Ignore transitions from pin to on or vice versa */
 		if (mode && xo_voter->mode == MSM_XO_MODE_OFF)
-			clk_enable(xo_clk);
+			clk_prepare_enable(xo_clk);
 		else if (!mode)
-			clk_disable(xo_clk);
+			clk_disable_unprepare(xo_clk);
 	}
 	xo_voter->mode = mode;
 out: