test/py: Start sandbox SPL when enabled

When sandbox SPL is enabled we want to start that rather than U-Boot proper,
since some tests may rely on running it first.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/py/u_boot_console_sandbox.py b/test/py/u_boot_console_sandbox.py
index 04654ae..6bf4653 100644
--- a/test/py/u_boot_console_sandbox.py
+++ b/test/py/u_boot_console_sandbox.py
@@ -39,11 +39,15 @@
             A u_boot_spawn.Spawn object that is attached to U-Boot.
         """
 
+        bcfg = self.config.buildconfig
+        config_spl = bcfg.get('config_spl', 'n') == 'y'
+        fname = '/spl/u-boot-spl' if config_spl else '/u-boot'
+        print fname
         cmd = []
         if self.config.gdbserver:
             cmd += ['gdbserver', self.config.gdbserver]
         cmd += [
-            self.config.build_dir + '/u-boot',
+            self.config.build_dir + fname,
             '-v',
             '-d',
             self.config.build_dir + '/arch/sandbox/dts/test.dtb'