Change in flashrom[master]: realtek_mst: add support for a devpath option

[Peter Marheine (Code Review)]

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Hello build bot (Jenkins),

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

https://review.coreboot.org/c/flashrom/+/52405

to look at the new patch set (#2).

Change subject: realtek_mst: add support for a devpath option
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realtek_mst: add support for a devpath option

As with the lspcon_i2c_spi programmer, it may be more convenient for
callers to specify the I2C bus by device path rather than number. Add
support for a 'devpath' option that is mutually exclusive with the 'bus'
option and specifies how to communicate with the target.

TEST=-p realtek_mst_i2c_spi:devpath=/dev/i2c-8 --flash-size works, bus=8
     continues to work. If both or neither are given, fails gracefully.

Change-Id: Ieea57b2445f3aca16c87d8f839dff131009531a0
---
M realtek_mst_i2c_spi.c
1 file changed, 49 insertions(+), 26 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/05/52405/2