usb clock update

Let musb_hdrc on DaVinci use the clock framework, now that it
seems to work right.

 * add USBCLK to dm644x support (it's already there for dm355)
 * only enable it when the driver asks for that
 * make the musb_hdrc driver use that clock

The original failures seem to have been caused by really buggy code
implementing the clock APIs.  Now they're working right.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/clock.c

@@ -317,6 +317,11 @@ static struct clk davinci_clks[] = {
 		.rate = &commonrate,
 		.lpsc = DAVINCI_LPSC_GPIO,
 	},
+	{
+		.name = "USBCLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_USB,
+	},
 	{
 		.name = "AEMIFCLK",
 		.rate = &commonrate,

arch/arm/mach-davinci/psc.c

@@ -218,8 +218,6 @@ void __init davinci_psc_init(void)
 					DAVINCI_LPSC_TPTC1, 1);
 		davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN,
 					DAVINCI_LPSC_GPIO, 1);
-		davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN,
-					DAVINCI_LPSC_USB, 1);
 
 		/* Turn on WatchDog timer LPSC.	 Needed for RESET to work */
 		davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN,

arch/arm/mach-davinci/usb.c

@@ -48,6 +48,7 @@ static struct musb_hdrc_platform_data usb_data = {
 #elif defined(CONFIG_USB_MUSB_HOST)
 	.mode           = MUSB_HOST,
 #endif
+	.clock		= "USBCLK",
 	.config		= &musb_config,
 };