ARM: OMAP1: usb: fix sparse warnings

Resolve the following sparse warnings:

arch/arm/mach-omap1/usb.c:304:12: warning: symbol 'omap1_usb0_init' was not declared. Should it be static?
arch/arm/mach-omap1/usb.c:412:12: warning: symbol 'omap1_usb1_init' was not declared. Should it be static?
arch/arm/mach-omap1/usb.c:478:12: warning: symbol 'omap1_usb2_init' was not declared. Should it be static?

by declaring those functions as static.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Felipe Balbi <balbi@ti.com>
[tony@atomide.com: this was missed with plat/usb.h removal]
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap1/usb.c

@@ -301,7 +301,7 @@ static inline void otg_device_init(struct omap_usb_config *pdata)
 
 #endif
 
-u32 __init omap1_usb0_init(unsigned nwires, unsigned is_device)
+static u32 __init omap1_usb0_init(unsigned nwires, unsigned is_device)
 {
 	u32	syscon1 = 0;
 
@@ -409,7 +409,7 @@ u32 __init omap1_usb0_init(unsigned nwires, unsigned is_device)
 	return syscon1 << 16;
 }
 
-u32 __init omap1_usb1_init(unsigned nwires)
+static u32 __init omap1_usb1_init(unsigned nwires)
 {
 	u32	syscon1 = 0;
 
@@ -475,7 +475,7 @@ bad:
 	return syscon1 << 20;
 }
 
-u32 __init omap1_usb2_init(unsigned nwires, unsigned alt_pingroup)
+static u32 __init omap1_usb2_init(unsigned nwires, unsigned alt_pingroup)
 {
 	u32	syscon1 = 0;