Kconfig: USB: Migrate CONFIG_USB_EHCI_HCD users to Kconfig

Migrate the rest of the users of CONFIG_USB_EHCI_HCD over to Kconfig.
For a few SoCs, imply or default y this if USB is enabled.  In some
cases we had not already migrated to CONFIG_USB so do that as well.

Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/configs/corvus_defconfig b/configs/corvus_defconfig
index ec6d1a4..36e6608 100644
--- a/configs/corvus_defconfig
+++ b/configs/corvus_defconfig
@@ -34,6 +34,7 @@
 CONFIG_DFU_NAND=y
 # CONFIG_MMC is not set
 CONFIG_USB=y
+CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_ATMEL_USBA=y