src: Rename 'ich_generation' to 'g_ich_generation'

The state of 'ich_generation' can be hard to follow where it is
currently global. Rename where appropriate to delinate the global state
from the local state passed in as an argument.

BRANCH=None
BUG=b:139255749
TEST=built

Change-Id: I07f6a6f52d8eeb4d3373ea08e5637f345633dfbc
Signed-off-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/1781978
Reviewed-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Andrew McRae <amcrae@chromium.org>
diff --git a/programmer.c b/programmer.c
index a4841db..a36102e 100644
--- a/programmer.c
+++ b/programmer.c
@@ -22,7 +22,7 @@
  * not compiled in, this is why they are exported through programmer.h and
  * defined here.
  */
-enum ich_chipset ich_generation = CHIPSET_ICH_UNKNOWN;
+enum ich_chipset g_ich_generation = CHIPSET_ICH_UNKNOWN;
 int ich_dry_run;
 
 static const struct par_master par_master_none = {