boost: put back chrono select for coroutine

coroutine module does use chrono directly:

./libs/coroutine/performance/asymmetric/segmented/Jamfile.v2: <library>/boost/chrono//boost_chrono
./libs/coroutine/performance/asymmetric/Jamfile.v2: <library>/boost/chrono//boost_chrono
./libs/coroutine/performance/symmetric/segmented/Jamfile.v2: <library>/boost/chrono//boost_chrono
./libs/coroutine/performance/symmetric/Jamfile.v2: <library>/boost/chrono//boost_chrono

So put back select of chrono for coroutine

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/boost/Config.in

@@ -101,6 +101,7 @@ config BR2_PACKAGE_BOOST_COROUTINE
 	bool "boost-coroutine"
 	depends on BR2_PACKAGE_BOOST_CONTEXT_ARCH_SUPPORTS
 	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735 # boost-context
+	select BR2_PACKAGE_BOOST_CHRONO
 	select BR2_PACKAGE_BOOST_CONTEXT
 	select BR2_PACKAGE_BOOST_SYSTEM
 	select BR2_PACKAGE_BOOST_THREAD