Update `pkg-config` and `imagemagick` (#428)

* add bsd to pkg-config

* add bsd to url download

* update imagemagick package to support bsd

packages/i/imagemagick/xmake.lua

@@ -51,7 +51,7 @@ package("imagemagick")
         end
     end)
 
-    on_install("linux", "macosx", function(package)
+    on_install("linux", "macosx", "bsd", function(package)
         local configs = {"--without-utilities",
                          "--without-x",
                          "--without-djvu",

packages/p/pkg-config/xmake.lua

@@ -4,13 +4,13 @@ package("pkg-config")
     set_homepage("https://freedesktop.org/wiki/Software/pkg-config/")
     set_description("A helper tool used when compiling applications and libraries.")
 
-    if is_host("macosx", "linux") then
+    if is_host("macosx", "linux", "bsd") then
         add_urls("https://pkgconfig.freedesktop.org/releases/pkg-config-$(version).tar.gz")
         add_urls("http://fco.it.distfiles.macports.org/mirrors/macports-distfiles/pkgconfig/pkg-config-$(version).tar.gz")
         add_versions("0.29.2", "6fc69c01688c9458a57eb9a1664c9aba372ccda420a02bf4429fe610e7e7d591")
     end
 
-    on_install("@macosx", "@linux", function (package)
+    on_install("@macosx", "@linux", "@bsd", function (package)
         local pcpath = {"/usr/local/lib/pkgconfig", "/usr/lib/pkgconfig"}
         if package:is_plat("linux") and package:is_arch("x86_64") then
             table.insert(pcpath, "/usr/lib/x86_64-linux-gnu/pkgconfig")