utils/genrandconfig: add mxs-bootlets custom handling

Add custom cases to make sure that a random configuration with an empty
git or tarball location for mxs-bootlets doesn't fail. It reverts to
BR2_TARGET_MXS_BOOTLETS_FREESCALE in that case.

Fixes:
 - http://autobuild.buildroot.org/results/dcbeb73d152c79c18b1fa3bef3b4fa07635d7b36
 - http://autobuild.buildroot.org/results/f61cf3fc58db9ded5ec42ebf4a9847584700698d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

utils/genrandconfig

@@ -543,6 +543,20 @@ def fixup_config(sysinfo, configfile):
         if 'BR2_ARCH_HAS_NO_TOOLCHAIN_BUILDROOT=y\n' in configlines:
             return False
 
+    if 'BR2_TARGET_MXS_BOOTLETS=y\n' in configlines and \
+       'BR2_TARGET_MXS_BOOTLETS_CUSTOM_GIT=y\n' in configlines and \
+       'BR2_TARGET_MXS_BOOTLETS_CUSTOM_GIT_URL=""\n' in configlines:
+        configlines.remove('BR2_TARGET_MXS_BOOTLETS_CUSTOM_GIT=y\n')
+        configlines.append('BR2_TARGET_MXS_BOOTLETS_FREESCALE=y\n')
+        configlines.remove('BR2_TARGET_MXS_BOOTLETS_CUSTOM_GIT_URL=""\n')
+
+    if 'BR2_TARGET_MXS_BOOTLETS=y\n' in configlines and \
+       'BR2_TARGET_MXS_BOOTLETS_CUSTOM_TARBALL=y\n' in configlines and \
+       'BR2_TARGET_MXS_BOOTLETS_CUSTOM_TARBALL_URL=""\n' in configlines:
+        configlines.remove('BR2_TARGET_MXS_BOOTLETS_CUSTOM_TARBALL=y\n')
+        configlines.append('BR2_TARGET_MXS_BOOTLETS_FREESCALE=y\n')
+        configlines.remove('BR2_TARGET_MXS_BOOTLETS_CUSTOM_TARBALL_URL=""\n')
+
     if 'BR2_TARGET_OPENSBI=y\n' in configlines and \
        'BR2_TARGET_OPENSBI_CUSTOM_GIT=y\n' in configlines and \
        'BR2_TARGET_OPENSBI_CUSTOM_REPO_URL=""\n' in configlines: