control: Add basic MCTP Control Protocol handler

This will respond to the 4 mandatory MCTP Control Protocol commands.
Applications can register supported types using mctp_control_add_type().

Change-Id: Ia904bcbe118626adf9254ffa71dd8e17fbdfc9b7
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
diff --git a/meson.options b/meson.options
index e3d9f9c..18b594e 100644
--- a/meson.options
+++ b/meson.options
@@ -43,3 +43,9 @@
     value: false,
     description: 'Don\'t include any logging functionality',
 )
+option(
+    'control',
+    type: 'boolean',
+    value: true,
+    description: 'Include MCTP control protocol handler',
+)