Don't search for symbols in the payloads directory, except for specific
files that are actively added back to the search.
Change-Id: I6f28dc7dee040b8061fa5644066f3613367b6d84
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/17443
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>