Include ec.config when swapping

If the ec.config path is given, or if it exists next to the ec.bin, then
swap it into the AP-RW cbfs also.

BUG=b:397764548
TEST=Ran script w/ -i and -e w/ ec.config next to ec.bin
TEST=Ran script w/ -i and -e w/o ec.config next to ec.bin
TEST=Ran script w/ -i, -e, and -ec_config with valid path
TEST=Ran script w/ -i, -e, and -ec_config with invalid path
TEST=Compared cbfstool print output in after each test
BRANCH=None

Change-Id: I372c20503ab33d5f6e91578ac353aaf0facd296c
Signed-off-by: Jeremy Bettis <jbettis@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/6302323
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Commit-Queue: Yu-Ping Wu <yupingso@chromium.org>
Auto-Submit: Jeremy Bettis <jbettis@chromium.org>
Tested-by: Jeremy Bettis <jbettis@chromium.org>
Reviewed-by: Wai-Hong Tam <waihong@google.com>