platform/chrome: Make depends on MFD_CROS_EC instead CROS_EC_PROTO

The ChromeOS EC LPC and chardev drivers depend on CROS_EC_PROTO but
MFD_CROS_EC select CROS_EC_PROTO instead. Mixing select and depends
on is bad practice as it may lead to circular Kconfig dependencies.

Since the platform devices that are matched with these drivers are
registered by the ChromeOS EC mfd driver, they really depend on
MFD_CROS_EC. And because this config option selects CROS_EC_PROTO,
that dependency is met as well. So make the drivers to depend on
MFD_CROS_EC instead of CROS_EC_PROTO.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

drivers/platform/chrome/Kconfig

@@ -40,7 +40,7 @@ config CHROMEOS_PSTORE
 
 config CROS_EC_CHARDEV
         tristate "Chrome OS Embedded Controller userspace device interface"
-        depends on CROS_EC_PROTO
+        depends on MFD_CROS_EC
         ---help---
           This driver adds support to talk with the ChromeOS EC from userspace.
 
@@ -49,7 +49,7 @@ config CROS_EC_CHARDEV
 
 config CROS_EC_LPC
         tristate "ChromeOS Embedded Controller (LPC)"
-        depends on MFD_CROS_EC && CROS_EC_PROTO && (X86 || COMPILE_TEST)
+        depends on MFD_CROS_EC && (X86 || COMPILE_TEST)
         help
           If you say Y here, you get support for talking to the ChromeOS EC
           over an LPC bus. This uses a simple byte-level protocol with a