package/libsigrok: drop remnants of autoreconf

libsigrok has not needed autoreconf since b428801934 (package/libsigrok:
bump version to 0.4.0), 4 years ago now.

As such, we no longer need the autoreconf options, nor the dependency on
the autoconf archive.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
Tested-by: Heiko Thiery <heiko.thiery@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 7ba7b9603b686524e1981e5251e9e25f5034d1bc)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libsigrok/libsigrok.mk

@@ -39,9 +39,7 @@ endif
 
 ifeq ($(BR2_PACKAGE_LIBSIGROKCXX),y)
 LIBSIGROK_CONF_OPTS += --enable-cxx
-LIBSIGROK_AUTORECONF_OPTS += -I $(HOST_DIR)/share/autoconf-archive
 LIBSIGROK_DEPENDENCIES += \
-	host-autoconf-archive \
 	glibmm \
 	host-doxygen \
 	$(if $(BR2_PACKAGE_PYTHON3),host-python3,host-python)