grove: KConfig cleanup

Adding in dependency of GROVE_DEBUG to the GROVE configuration
option being set

Change-Id: I4108e619254ca3cde2b96de595e1b8300fe6a752
Signed-off-by: Dan Kalowsky <daniel.kalowsky@intel.com>
diff --git a/drivers/grove/Kconfig b/drivers/grove/Kconfig
index 671f44b..3cf96f4 100644
--- a/drivers/grove/Kconfig
+++ b/drivers/grove/Kconfig
@@ -28,6 +28,7 @@
         bool
         prompt "Enable Grove debug messagings"
         default n
+        depends on GROVE
 
 config GROVE_LCD_RGB
         bool