[S] Change in coreboot[main]: arch/riscv: Allow adding OpenSBI as external blob

[Maximilian Brune (Code Review)]

Attention is currently required from: Maximilian Brune, Philipp Hug, ron minnich.

Hello Philipp Hug, build bot (Jenkins), ron minnich,

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

https://review.coreboot.org/c/coreboot/+/83284?usp=email

to look at the new patch set (#3).

The following approvals got outdated and were removed:
Code-Review+2 by ron minnich, Verified+1 by build bot (Jenkins)

Change subject: arch/riscv: Allow adding OpenSBI as external blob
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arch/riscv: Allow adding OpenSBI as external blob

The reasoning is that even though vendors currently tend to open source
their OpenSBI implementation, they often do so in their own repository.
So instead of adding all possible source repositories as submodules, we
shall allow specifying a path to an already compiled OpenSBI ELF file.
This is similar of what we currently do on ARM64 with the BL31 binary.

Signed-off-by: Maximilian Brune 
Change-Id: I6592ad90a254ca4ac9a6cee89404ad49274f0dea
---
M src/arch/riscv/Kconfig
M src/arch/riscv/Makefile.mk
2 files changed, 24 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/84/83284/3