am33xx: board: Refactor USB initialization into separate function

The declaration of otg*_plat and otg*_board_data is guarded by
CONFIG_USB_MUSB_*, but their use in arch_misc_init is not. The
ifdef flow goes something like:

if (CONFIG_USB_MUSB_* && other_conditions)
	declare usb_data
if (other_conditions)
	use usb_data

Thus when CONFIG_USB_MUSB_* is not declared, we try to use the
data structures, but these structures aren't defined.

To fix this, move the USB initialization code into the same #ifdef
which guards the declaration of the data structures. Since the DM_USB
vs legacy cases are completely different, use two versions of
arch_misc_init(), for readability.

Signed-off-by: Alexandru Gagniuc <alex.g@adaptrum.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/mach-omap2/am33xx/board.c

@@ -213,11 +213,9 @@ static struct musb_hdrc_platform_data otg1_plat = {
 	.board_data	= &otg1_board_data,
 };
 #endif
-#endif
 
 int arch_misc_init(void)
 {
-#ifndef CONFIG_DM_USB
 #ifdef CONFIG_AM335X_USB0
 	musb_register(&otg0_plat, &otg0_board_data,
 		(void *)USB0_OTG_BASE);
@@ -226,7 +224,13 @@ int arch_misc_init(void)
 	musb_register(&otg1_plat, &otg1_board_data,
 		(void *)USB1_OTG_BASE);
 #endif
-#else
+	return 0;
+}
+
+#else	/* CONFIG_USB_MUSB_* && CONFIG_AM335X_USB* && !CONFIG_DM_USB */
+
+int arch_misc_init(void)
+{
 	struct udevice *dev;
 	int ret;
 
@@ -241,10 +245,12 @@ int arch_misc_init(void)
 		return ret;
 	}
 #endif
-#endif
+
 	return 0;
 }
 
+#endif /* CONFIG_USB_MUSB_* && CONFIG_AM335X_USB* && !CONFIG_DM_USB */
+
 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 /*
  * In the case of non-SPL based booting we'll want to call these