programmer: Add rget_io_perms programmer req framework

Some programmers require special i/o port access permissions.
Add a flag in the programmer entry to allow the programmer to
flag this requirement to the flashrom core logic rather than
each bespoke programmer init() calling rget_io_perms() in their
own ways.

This allows for flashrom core logic to assume and drop privileges
exactly where they are needed rather than for the entire life-time
of the program. It also deduplicates the assuming privilege code in
each driver.

Change-Id: I2be81995f8fe7e212a01008a5e7bdb49b1592ca2
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
---
M flashrom.c
M include/programmer.h
2 files changed, 30 insertions(+), 0 deletions(-)