Change in coreboot[master]: Allow to build romstage sources inside the bootblock

[Arthur Heymans (Code Review)]

Attention is currently required from: Martin Roth, ron minnich, Paul Menzel, Stefan Reinauer, Julius Werner, Angel Pons, Keith Hui, Patrick Rudolph, Felix Held.
Hello build bot (Jenkins), Raul Rangel, Furquan Shaikh, Philipp Hug, ron minnich, Stefan Reinauer, Subrata Banik, Julius Werner, Andrey Petrov, Aaron Durbin, Patrick Rudolph, Piotr Król, Jason Glenesk, Michał Żygowski, Martin Roth, Marshall Dawson, ron minnich, Felix Held,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/55068

to look at the new patch set (#12).

Change subject: Allow to build romstage sources inside the bootblock
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Allow to build romstage sources inside the bootblock

Having a separate romstage is only desirable:
 - with advanced setups like vboot or normal/fallback
 - boot medium is slow at startup (some ARM SOCs)
 - bootblock is limited in size (Intel APL 32K)

When this is not the case there is no need for the extra complexity
that romstage brings. Including the romstage sources inside the
bootblock substantially reduces the total code footprint. Often the
resulting code is 10-20k smaller.

This is controlled via a Kconfig option.

TESTED: works on qemu x86, arm and aarch64.

Change-Id: Id68390edc1ba228b121cca89b80c64a92553e284
Signed-off-by: Arthur Heymans 
---
M Makefile.inc
M src/Kconfig
M src/arch/arm64/romstage.c
M src/arch/x86/Makefile.inc
M src/include/rules.h
M src/lib/prog_loaders.c
M src/mainboard/emulation/qemu-armv7/romstage.c
7 files changed, 30 insertions(+), 5 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/55068/12