DaVinci: rename setup_usb() to davinci_setup_usb()

Rename setup_usb() into davinci_setup_usb().  While at it:

- move its declaration from <mach/common.h> to more fitting <mach/usb.h>;
- teach it to handle values of the 'mA' parameter greater than 510 and thus
  pass 1000 instead of 500 for the power switches capable of sourcing over 1 A;
- teach it to handle odd values of the 'potpgt_ms' parameter...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/usb.c b/arch/arm/mach-davinci/usb.c
index 31eec87..fe20cc2 100644
--- a/arch/arm/mach-davinci/usb.c
+++ b/arch/arm/mach-davinci/usb.c
@@ -83,10 +83,10 @@
 	.num_resources  = ARRAY_SIZE(usb_resources),
 };
 
-void __init setup_usb(unsigned mA, unsigned potpgt_msec)
+void __init davinci_setup_usb(unsigned mA, unsigned potpgt_ms)
 {
-	usb_data.power = mA / 2;
-	usb_data.potpgt = potpgt_msec / 2;
+	usb_data.power = mA > 510 ? 255 : mA / 2;
+	usb_data.potpgt = (potpgt_ms + 1) / 2;
 
 	if (cpu_is_davinci_dm646x()) {
 		/* Override the defaults as DM6467 uses different IRQs. */
@@ -100,7 +100,7 @@
 
 #else
 
-void __init setup_usb(unsigned mA, unsigned potpgt_msec)
+void __init davinci_setup_usb(unsigned mA, unsigned potpgt_ms)
 {
 }