usb: musb: Fix compile error for omaps for musb_hdrc

CONFIG_ARCH_OMAP34XX is now CONFIG_ARCH_OMAP3.

But since drivers/usb/musb/omap2430.c use CONFIG_PM for these
registers and functions, do the same for the header.

Otherwise we get the following for most omap3 defconfigs:

drivers/usb/musb/omap2430.c:261: error: expected identifier or '(' before 'do'
drivers/usb/musb/omap2430.c:261: error: expected identifier or '(' before 'while'
drivers/usb/musb/omap2430.c:268: error: expected identifier or '(' before 'do'
drivers/usb/musb/omap2430.c:268: error: expected identifier or '(' before 'while'

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_core.h

@@ -469,7 +469,7 @@ struct musb_csr_regs {
 
 struct musb_context_registers {
 
-#if defined(CONFIG_ARCH_OMAP34XX) || defined(CONFIG_ARCH_OMAP2430)
+#ifdef CONFIG_PM
 	u32 otg_sysconfig, otg_forcestandby;
 #endif
 	u8 power;
@@ -483,7 +483,7 @@ struct musb_context_registers {
 	struct musb_csr_regs index_regs[MUSB_C_NUM_EPS];
 };
 
-#if defined(CONFIG_ARCH_OMAP34XX) || defined(CONFIG_ARCH_OMAP2430)
+#ifdef CONFIG_PM
 extern void musb_platform_save_context(struct musb *musb,
 		struct musb_context_registers *musb_context);
 extern void musb_platform_restore_context(struct musb *musb,