soc/amd/stoneyridge: Update amdfw build

- The SMU firmware used to be named *.sbin, now is named *.csbin.
Update the makefile so that the files can be named as they are
delivered and don't have to be renamed.
- Add a Kconfig option to allow the secure os binaries to be excluded.

BUG=b:64932297
TEST=Build with old and new firmware, verify file sizes.

Change-Id: I3091f8af126159488c3c398a6dc881fa05039cff
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/21450
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
2 files changed