ARM: UniPhier: remove EHCI platform devices

Now UniPhier platform highly depends on Device Tree configuration
(CONFIG_OF_CONTROL is select'ed by Kconfig).  Since the EHCI is only
used on main U-Boot, we can drop platform devices of the EHCI
controllers.  We still keep UART platform devices because they might
be useful for SPL.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 30d1457..0e005c2 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -47,7 +47,7 @@
 
 config USB_EHCI_UNIPHIER
 	bool "Support for Panasonic UniPhier on-chip EHCI USB controller"
-	depends on ARCH_UNIPHIER
+	depends on ARCH_UNIPHIER && OF_CONTROL
 	default y
 	---help---
 	  Enables support for the on-chip EHCI controller on Panasonic