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/smdk5250_defconfig b/configs/smdk5250_defconfig
index ff52a37..c51df50 100644
--- a/configs/smdk5250_defconfig
+++ b/configs/smdk5250_defconfig
@@ -48,6 +48,7 @@
 CONFIG_DM_USB=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
+CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y
 CONFIG_VIDEO_BRIDGE=y
 CONFIG_ERRNO_STR=y