add autocomplete for adb -s option (#6121)

plugins/adb/README.md

 # adb autocomplete plugin
 
 * Adds autocomplete options for all adb commands.
-
+* Add autocomplete for `adb -s`
 
 ## Requirements
 

plugins/adb/_adb

@@ -43,8 +43,17 @@ local expl
 local -a pkgs installed_pkgs
 
 _arguments \
+	'-s[devices]:specify device:->specify_device' \
 	'*:: :->subcmds' && return 0
 
+case "$state" in
+	specify_device)
+	_values  'devices' $(adb devices|awk 'NR>1&& $1 ~ /^[a-zA-Z0-9].*$/ \
+		{printf "%s[Device_%d:%s] ",$1,++i,$2 }')
+	return
+	;;
+esac
+
 if (( CURRENT == 1 )); then
 	_describe -t commands "adb subcommand" _1st_arguments
 	return