debug: ztest: reduce delay between tests

Currently ztest delay is set to 100ms, which adds that time between
each too ztest runs. This very quickly adds up to cause an IPC
timeout in the kernel driver. That timeout isn't needed for SOF, set
it to 1ms.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

app/debug_overlay.conf

@@ -3,6 +3,7 @@ CONFIG_ASSERT=y
 
 CONFIG_ZTEST_NO_YIELD=n
 CONFIG_ZTEST_SUMMARY=n
+CONFIG_ZTEST_TEST_DELAY_MS=1
 CONFIG_SOF_BOOT_TEST_ALLOWED=y
 CONFIG_TEST_EXTRA_STACK_SIZE=7168