package/libllcp: drop wrong comment

Dependency on threads comes from libllcp itself not from libusb (which
is not even selected)

While at it, also add a comment about this dependency

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

package/libllcp/Config.in

@@ -1,9 +1,12 @@
 config BR2_PACKAGE_LIBLLCP
 	bool "libllcp"
-	depends on BR2_TOOLCHAIN_HAS_THREADS # libusb
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_LIBNFC
 	help
 	  Library extending libnfc with support for Logical Link Control
 	  Protocol.
 
 	  https://github.com/nfc-tools/libllcp
+
+comment "libllcp needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS