sketchybar: set supported_arch and build for correct architecture

sysutils/sketchybar/Portfile

@@ -15,6 +15,7 @@ maintainers             {@bashu gmail.com:bashu.was.here} openmaintainer
 license                 GPL-3
 name                    sketchybar
 revision                0
+supported_archs         x86_64 arm64
 description             Custom macOS statusbar with shell plugin, interaction and graph support
 long_description        This bar project aims to create a highly flexible, \
                         customizable, fast and powerful status bar replacement \
@@ -33,6 +34,15 @@ post-patch {
     reinplace "s|@PREFIX@|${prefix}|g" ${worksrcpath}/org.macports.${name}.plist
 }
 
+
+if {${configure.build_arch} == "x86_64"} {
+    build.target "x86"
+} elseif {${configure.build_arch} == "arm64"} {
+    build.target "arm64"
+} elseif {${universal_possible}} {
+    build.target "universal"
+}
+
 destroot {
     # Copy binary
     xinstall -m 755 ${worksrcpath}/bin/sketchybar ${destroot}${prefix}/bin/sketchybar