Convert CONFIG_USB_KEYBOARD to Kconfig

This converts the following to Kconfig:
   CONFIG_USB_KEYBOARD

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: Fixup MPC86* configs]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/smdk2410_defconfig b/configs/smdk2410_defconfig
index d6aa2dd..c84ce52 100644
--- a/configs/smdk2410_defconfig
+++ b/configs/smdk2410_defconfig
@@ -14,3 +14,4 @@
 CONFIG_CMD_UBI=y
 CONFIG_USB=y
 CONFIG_USB_STORAGE=y
+CONFIG_USB_KEYBOARD=y