package/ltris: drop unrecognized option

--enable-sound has been dropped since version 1.2.4 and
https://sourceforge.net/p/lgames/code/432:

configure: WARNING: unrecognized options: --disable-gtk-doc, --disable-gtk-doc-html, --disable-doc, --disable-docs, --disable-documentation, --with-xmlto, --with-fop, --enable-ipv6, --enable-static, --disable-shared, --enable-sound

Fixes: 61848605cd26d29f54c16de862aedba7cf334be4

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 9af20d6e1e1139e59ed3dd9aaf015e72f1e2db8e)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ltris/ltris.mk

@@ -18,12 +18,9 @@ LTRIS_CONF_ENV = \
 
 ifeq ($(BR2_PACKAGE_LTRIS_AUDIO),y)
 LTRIS_DEPENDENCIES += sdl_mixer host-pkgconf
-LTRIS_CONF_OPTS += --enable-sound
 # configure script does NOT use pkg-config to figure out how to link
 # with sdl_mixer, breaking static linking as sdl_mixer can use libmad
 LTRIS_LIBS += `$(PKG_CONFIG_HOST_BINARY) --libs SDL_mixer`
-else
-LTRIS_CONF_OPTS += --disable-sound
 endif
 
 $(eval $(autotools-package))