picocom: add license info

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/picocom/picocom.mk

@@ -6,6 +6,8 @@
 
 PICOCOM_VERSION = 1.7
 PICOCOM_SITE    = http://picocom.googlecode.com/files/
+PICOCOM_LICENSE = GPLv2+
+PICOCOM_LICENSE_FILES = LICENSE.txt
 
 define PICOCOM_BUILD_CMDS
 	$(TARGET_CONFIGURE_OPTS) $(MAKE) -C $(@D)