webp: minor improvements

Following commit e47638f8dca29b0d9b729edbaeaa11a08f9957fa, this commit
makes a few additional cosmetic improvements to the webp package.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/webp/Config.in

@@ -6,10 +6,13 @@ config BR2_PACKAGE_WEBP
 
 	  https://developers.google.com/speed/webp/
 
+if BR2_PACKAGE_WEBP
+
 config BR2_PACKAGE_WEBP_DEMUX
 	bool "webpdemux"
-	depends on BR2_PACKAGE_WEBP
 	help
-	  "Demux" is a part of WebPMux for extraction and manipulation of an
-	  extended format WebP file, which can have features like color profile,
-	  metadata and animation.
+	  Demux is a part of WebPMux for extraction and manipulation
+	  of an extended format WebP file, which can have features
+	  like color profile, metadata and animation.
+
+endif

package/webp/webp.mk

@@ -19,6 +19,8 @@ WEBP_CONF_OPTS += \
 
 ifeq ($(BR2_PACKAGE_WEBP_DEMUX),y)
 WEBP_CONF_OPTS += --enable-libwebpdemux
+else
+WEBP_CONF_OPTS += --disable-libwebpdemux
 endif
 
 ifeq ($(BR2_PACKAGE_LIBPNG),y)