systemc: Change the default "catch action" to SC_DISPLAY.

There is a test which checks what it was and asserts if it's something
else.

Change-Id: I114c0a38c9fa69544416a4d1b555bb87e6246efd
Reviewed-on: https://gem5-review.googlesource.com/c/13306
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
1 file changed