Add Gemini Lake support

The SPI hardware is pretty much unchanged from Apollo Lake. However, the
IFD differs significantly enough to require special handling.

Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Change-Id: Ib5dcdf204166f44a8531c19b5f363b851d2ccd77
Reviewed-on: https://review.coreboot.org/c/flashrom/+/54276
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

programmer.h

@@ -672,6 +672,7 @@ enum ich_chipset {
 	CHIPSET_300_SERIES_CANNON_POINT,
 	CHIPSET_APOLLO_LAKE,
 	CHIPSET_400_SERIES_COMET_POINT,
+	CHIPSET_GEMINI_LAKE,
 };
 
 /* ichspi.c */