mb/{kontron/bsl6,siemens/chili}: Add `inhibit_flashlock` nvram option

Change-Id: I8c5d6686bf7c694f9d594e3801c79cfd7fb3da80
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56342
Reviewed-by: Maxim Polyakov <max.senia.poliak@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/kontron/bsl6/cmos.layout

@@ -22,6 +22,7 @@ entries
 440	1	e	2	ethernet1
 441	1	e	2	ethernet2
 442	1	e	2	ethernet3
+443	1	e	1	inhibit_flashlock
 
 # payload config options
 512	256	s	0	boot_devices

src/mainboard/siemens/chili/cmos.layout

@@ -23,6 +23,7 @@ entries
 
 # coreboot config options: mainboard
 440	1	e	2	ethernet1
+441	1	e	1	inhibit_flashlock
 
 # payload config options
 512	256	s	0	boot_devices