Hack in hyperdebug support for tests

This hack allows the `cw310_params` block to override the interface to
support running cw310 tests via the hyperdebug board rather than via the
native cw310 interface.

This is a temporary hack: properly integrating hyperdebug for cw310 FPGA
tests will be done in a series of follow-up PRs.

Signed-off-by: Chris Frantz <cfrantz@google.com>
diff --git a/rules/opentitan_test.bzl b/rules/opentitan_test.bzl
index e5a59c0..77ac8f5 100644
--- a/rules/opentitan_test.bzl
+++ b/rules/opentitan_test.bzl
@@ -190,6 +190,7 @@
         clear_bitstream = False,
         # None
         timeout = "short",
+        interface = "cw310",
         **kwargs):
     """A macro to create CW310 parameters for OpenTitan functional tests.
 
@@ -217,7 +218,7 @@
         "--logging={logging}",
     ]
     required_test_cmds = [
-        "--interface=cw310",
+        "--interface={}".format(interface),
     ]
     required_tags = [
         "cw310",