package/pulseview: drop boost thread

Since bump to 0.4.0, boost thread is not needed anymore:
https://sigrok.org/gitweb/?p=pulseview.git;a=commit;h=b8f1cdeba7cf6c2b749ff60102ce4e260fa1309e

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

package/pulseview/Config.in

@@ -18,7 +18,6 @@ config BR2_PACKAGE_PULSEVIEW
 	select BR2_PACKAGE_BOOST
 	select BR2_PACKAGE_BOOST_FILESYSTEM
 	select BR2_PACKAGE_BOOST_SYSTEM
-	select BR2_PACKAGE_BOOST_THREAD
 	select BR2_PACKAGE_BOOST_SERIALIZATION
 	help
 	  PulseView is a Qt based logic analyzer, oscilloscope