Add bootloadertype support

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
diff --git a/lava-submit.py b/lava-submit.py
index 8e3eb86..0012cce 100755
--- a/lava-submit.py
+++ b/lava-submit.py
@@ -273,6 +273,11 @@
                    {
                        'command': 'boot_linaro_image'
                    }]
+
+        bootloader = os.environ.get('BOOTLOADER')
+        if bootloader is not None:
+            actions[0]['parameters'].update(json.loads('{"bootloadertype": "%s"}' % bootloader))
+
     elif distribution == 'ubuntu' or distribution == 'quantal' or distribution == 'raring':
         actions = [{
                        'command': 'deploy_linaro_image',