nitrogen6x: use alternative boot for rollback

Provide configuration for SabreLite board for alternative boot
usage in case if `bootlimit` reached. This is needed to rollback
the device to previous boot with additional boot config.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

debian/patches/apertis/imx6/0004-nitrogen6x-use-alternative-boot-for-rollback.patch

+From 13000465b7ba5903efbd250ab2ccbfa307e51bd7 Mon Sep 17 00:00:00 2001
+From: Denis Pynkin <denis.pynkin@collabora.com>
+Date: Thu, 1 Nov 2018 19:43:36 +0000
+Subject: [PATCH 4/6] nitrogen6x: use alternative boot for rollback
+
+Provide configuration for SabreLite board for alternative boot
+usage in case if `bootlimit` reached. This is needed to rollback
+the device to previous boot with additional boot config.
+
+Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>
+---
+ include/configs/nitrogen6x.h | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/include/configs/nitrogen6x.h b/include/configs/nitrogen6x.h
+index 9ef6ea90..be6c4dea 100644
+--- a/include/configs/nitrogen6x.h
++++ b/include/configs/nitrogen6x.h
+@@ -127,6 +127,10 @@
+ 	"ramdiskaddr=0x13000000\0" \
+ 	"ip_dyn=yes\0" \
+ 	"usb_pgood_delay=2000\0" \
++	"bootlimit=3\0" \
++	"altbootcmd=" \
++	"setenv boot_syslinux_conf \"extlinux/extlinux-rollback.conf\"; " \
++	"run distro_bootcmd\0"\
+ 	BOOTENV
+ 
+ /* Miscellaneous configurable options */
+-- 
+2.25.4
+

debian/patches/series

@@ -48,3 +48,4 @@ apertis/rpi/0004-RPi-enable-FIT-images-support.patch
 apertis/imx6/0001-Switch-SabreLite-to-storing-ENV-in-SPI.patch
 apertis/imx6/0002-mx6sabrelite-Enable-gigadevice-nor-flashes.patch
 apertis/imx6/0003-mx6sabrelite-enable-bootcount.patch
+apertis/imx6/0004-nitrogen6x-use-alternative-boot-for-rollback.patch