[S] Change in flashrom[master]: flashrom.c: Confine is_internal checks under a symbol

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Felix Singer, Thomas Heijligen, Angel Pons, Anastasia Klimchuk.

Edward O'Callaghan has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/67475 )

Change subject: flashrom.c: Confine is_internal checks under a symbol
......................................................................

Patch Set 2:

(1 comment)

Commit Message:

https://review.coreboot.org/c/flashrom/+/67475/comment/531ace01_470909d0 
PS1, Line 9: We
> Who is "we"?

I meant it in the scientific writing sense of 'we require for printers to be pure* functions'. Could be rephrased I suppose? This change and CB:67476 are strongly related. The idea is to know we are the internal programmer by way of a flag over needing to interrogate a stack pointer address.