SPD sources for Dedede and Volteer are being auto-generated by SPD
tools now, and so we can remove SPD_SOURCES from Makefile.inc for
those templates. That makes Makefile.inc empty for those reference
boards, so remove Makefile.inc from the templates.
BUG=b:158492307
BRANCH=None
TEST=Create new variant of volteer, waddledee, and waddledoo, and
verify that we can still build the coreboot image.
Signed-off-by: Paul Fagerburg <pfagerburg@google.com>
Change-Id: Iba5264384302300cc8d2256a6b43f3353770154a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42204
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>