[meson] Pull the functionality of make_build_bin.sh into Meson.

This change is part of the effort to implement the directory structure
described in #650.

Signed-off-by: Miguel Young de la Sota <mcyoung@google.com>
diff --git a/meson_options.txt b/meson_options.txt
index 957be04..80f43d2 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,4 +1,25 @@
-option('target', type : 'combo', choices: ['sim-verilator', 'fpga', 'undef'], value : 'undef')
+option(
+  'target',
+  type: 'combo',
+  choices: [
+    'sim-verilator',
+    'fpga',
+    'undef',
+  ],
+  value: 'undef',
+)
+
+option(
+  'dev_bin_dir',
+  type: 'string',
+  value: 'undef',
+)
+
+option(
+  'host_bin_dir',
+  type: 'string',
+  value: 'undef',
+)
 
 option(
   'ot_version',