USB: remove USB_EHCI_BIG_ENDIAN_{DESC,MMIO} depends on architecture symbol

Just like the OHCI counter part we just can remove the architecture
specific symbols which prevent these configuration symbols from being
selected by platforms/architectures requiring it. The original
implementation did not scale at all since it required each and every
single architecture to be added for these configuration symbols to be
selected. Now it is up to the EHCI driver and/or platform to select
these configuration symbols accordingly.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/powerpc/platforms/44x/Kconfig

@@ -274,6 +274,8 @@ config 440EPX
 	select IBM_EMAC_EMAC4
 	select IBM_EMAC_RGMII
 	select IBM_EMAC_ZMII
+	select USB_EHCI_BIG_ENDIAN_MMIO
+	select USB_EHCI_BIG_ENDIAN_DESC
 
 config 440GRX
 	bool