lttng-babeltrace: add missing select BR2_PACKAGE_POPT

lttng-babeltrace unconditionally uses "popt" in its <pkg>_DEPENDENCIES
variable, but does not select it. This commit fixes this
inconsistency.

Fixes:

  http://autobuild.buildroot.org/results/274/2748a02b090ce078fc880bd821df3c913b8c8dfd/

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

package/lttng-babeltrace/Config.in

@@ -3,6 +3,7 @@ config BR2_PACKAGE_LTTNG_BABELTRACE
 	select BR2_PACKAGE_UTIL_LINUX
 	select BR2_PACKAGE_UTIL_LINUX_LIBUUID
 	select BR2_PACKAGE_LIBGLIB2
+	select BR2_PACKAGE_POPT
 	depends on BR2_USE_WCHAR # libglib2, util-linux
 	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib2
 	depends on BR2_USE_MMU # libglib2