staging: gdm72xx: WIMAX_GDM72XX_USB_PM should depend on USB_SUSPEND

Use Kconfig logic instead of a rude #error in the driver source,
which breaks m68k-allmodconfig.
Also remove the "default n", as that's the default.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Sage Ahn <syahn@gctsemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gdm72xx/Kconfig

@@ -38,7 +38,7 @@ if WIMAX_GDM72XX_USB
 
 config WIMAX_GDM72XX_USB_PM
 	bool "Enable power managerment support"
-	default n
+	depends on USB_SUSPEND
 
 endif # WIMAX_GDM72XX_USB
 

drivers/staging/gdm72xx/gdm_usb.c

@@ -17,12 +17,6 @@
 #include <linux/usb.h>
 #include <asm/byteorder.h>
 
-#ifdef CONFIG_WIMAX_GDM72XX_USB_PM
-#ifndef CONFIG_USB_SUSPEND
-#error "USB host doesn't support USB Selective Suspend."
-#endif
-#endif
-
 #include "gdm_usb.h"
 #include "gdm_wimax.h"
 #include "usb_boot.h"