broadcom/cygnus: add secimage and sign bootblock

secimage is a tool which adds a header and signature to the binary
first loaded by the soc. ARM core frequency is set to 1 Ghz.

BUG=chrome-os-partner:36421
BRANCH=broadcom-firmware
TEST=booted b0 board

Change-Id: Ia08600d45c47ee4f08d253980036916e44b0044a
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 36284d1b242c26b0b5aac2894f7ed1790da1ef15
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chrome-internal-review.googlesource.com/197155
Original-Reviewed-by: Scott Branden <sbranden@broadcom.com>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Commit-Queue: Daisuke Nojiri <dnojiri@google.com>
Original-Tested-by: Daisuke Nojiri <dnojiri@google.com>
Original-Change-Id: Iaddd24006b368c8f37e075cb51e151e985029f3b
Original-Reviewed-on: https://chromium-review.googlesource.com/264417
Reviewed-on: http://review.coreboot.org/9914
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/Makefile.inc b/Makefile.inc
index 9851461..04e8085 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -54,7 +54,7 @@
 # root source directories of coreboot
 subdirs-y := src/lib src/console src/device src/ec src/southbridge src/soc
 subdirs-y += src/northbridge src/superio src/drivers src/cpu src/vendorcode
-subdirs-y += util/cbfstool util/sconfig util/nvramtool
+subdirs-y += util/cbfstool util/sconfig util/nvramtool util/broadcom
 subdirs-y += src/arch/arm src/arch/arm64 src/arch/mips src/arch/riscv
 subdirs-y += src/arch/x86
 subdirs-y += src/mainboard/$(MAINBOARDDIR)