mplayer: use UTF-8 charset to avoid iconv dependency

The mplayer configure script was failing with:

  Checking for iconv program ... no
  No working iconv program found, use
  --charset=UTF-8 to continue anyway.
  If you also have problems with iconv library functions use --charset=noconv.
  Messages in the GTK-2 interface will be broken then.

Therefore, we pass --charset=UTF-8 instead of --charset=US-ASCII.

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

package/multimedia/mplayer/mplayer.mk

@@ -54,7 +54,7 @@ $(MPLAYER_DIR)/.configured: $(MPLAYER_DIR)/.unpacked
 		--as=$(TARGET_CROSS)as \
 		--with-extraincdir=$(STAGING_DIR)/usr/include \
 		--with-extralibdir=$(STAGING_DIR)/lib \
-		--charset=US-ASCII \
+		--charset=UTF-8 \
 		--enable-mad \
 		--enable-fbdev \
 		$(MPLAYER_ENDIAN) \