mfd: omap-usb: prepare/unprepare clock while enable/disable

This should fix the following warning at boot on OMAP5 uEVM
[    8.783155] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:883 __clk_enable+0x94/0xa4()

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c
index 1b65ffe..142650f 100644
--- a/drivers/mfd/omap-usb-host.c
+++ b/drivers/mfd/omap-usb-host.c
@@ -328,13 +328,13 @@
 	omap_tll_enable(pdata);
 
 	if (!IS_ERR(omap->ehci_logic_fck))
-		clk_enable(omap->ehci_logic_fck);
+		clk_prepare_enable(omap->ehci_logic_fck);
 
 	for (i = 0; i < omap->nports; i++) {
 		switch (pdata->port_mode[i]) {
 		case OMAP_EHCI_PORT_MODE_HSIC:
 			if (!IS_ERR(omap->hsic60m_clk[i])) {
-				r = clk_enable(omap->hsic60m_clk[i]);
+				r = clk_prepare_enable(omap->hsic60m_clk[i]);
 				if (r) {
 					dev_err(dev,
 					 "Can't enable port %d hsic60m clk:%d\n",
@@ -343,7 +343,7 @@
 			}
 
 			if (!IS_ERR(omap->hsic480m_clk[i])) {
-				r = clk_enable(omap->hsic480m_clk[i]);
+				r = clk_prepare_enable(omap->hsic480m_clk[i]);
 				if (r) {
 					dev_err(dev,
 					 "Can't enable port %d hsic480m clk:%d\n",
@@ -354,7 +354,7 @@
 
 		case OMAP_EHCI_PORT_MODE_TLL:
 			if (!IS_ERR(omap->utmi_clk[i])) {
-				r = clk_enable(omap->utmi_clk[i]);
+				r = clk_prepare_enable(omap->utmi_clk[i]);
 				if (r) {
 					dev_err(dev,
 					 "Can't enable port %d clk : %d\n",
@@ -382,15 +382,15 @@
 		switch (pdata->port_mode[i]) {
 		case OMAP_EHCI_PORT_MODE_HSIC:
 			if (!IS_ERR(omap->hsic60m_clk[i]))
-				clk_disable(omap->hsic60m_clk[i]);
+				clk_disable_unprepare(omap->hsic60m_clk[i]);
 
 			if (!IS_ERR(omap->hsic480m_clk[i]))
-				clk_disable(omap->hsic480m_clk[i]);
+				clk_disable_unprepare(omap->hsic480m_clk[i]);
 		/* Fall through as utmi_clks were used in HSIC mode */
 
 		case OMAP_EHCI_PORT_MODE_TLL:
 			if (!IS_ERR(omap->utmi_clk[i]))
-				clk_disable(omap->utmi_clk[i]);
+				clk_disable_unprepare(omap->utmi_clk[i]);
 			break;
 		default:
 			break;
@@ -398,7 +398,7 @@
 	}
 
 	if (!IS_ERR(omap->ehci_logic_fck))
-		clk_disable(omap->ehci_logic_fck);
+		clk_disable_unprepare(omap->ehci_logic_fck);
 
 	omap_tll_disable(pdata);