waf: allow build with "./waf iofirmware"

libraries/AP_IOMCU/iofirmware/wscript

@@ -21,5 +21,5 @@ def build(bld):
     bld.ap_program(
         program_name='iofirmware',
         use='iofirmware_libs',
-        program_groups=['bin'],
+        program_groups=['bin','iofirmware'],
     )

wscript

@@ -466,7 +466,7 @@ ardupilotwaf.build_command('check-all',
     doc='shortcut for `waf check --alltests`',
 )
 
-for name in ('antennatracker', 'copter', 'heli', 'plane', 'rover', 'sub', 'bootloader'):
+for name in ('antennatracker', 'copter', 'heli', 'plane', 'rover', 'sub', 'bootloader','iofirmware'):
     ardupilotwaf.build_command(name,
         program_group_list=name,
         doc='builds %s programs' % name,