openocd: CMSIS DAP support (for HEAD)

Closes Homebrew/homebrew#26672.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/open-ocd.rb

@@ -8,9 +8,14 @@ class OpenOcd < Formula
   head do
     url 'git://git.code.sf.net/p/openocd/code'
 
+    option 'enable-cmsis-dap', 'Enable building support for devices using CMSIS-DAP'
+
     depends_on :autoconf
     depends_on :automake
     depends_on :libtool
+    depends_on 'pkg-config' => :build
+
+    depends_on 'hidapi' if build.include? 'enable-cmsis-dap'
   end
 
   option 'enable-ft2232_libftdi', 'Enable building support for FT2232 based devices with libftdi driver'
@@ -50,6 +55,10 @@ class OpenOcd < Formula
       args << "--enable-presto_ftd2xx"
     end
 
+    if build.head? && build.include?("enable-cmsis-dap")
+      args << "--enable-cmsis-dap"
+    end
+
     ENV['CCACHE'] = 'none'
 
     system "./bootstrap", "nosubmodule" if build.head?