watchdog's patches backport from dev to 2.7/warrior

[Ivan Mikhaylov]

Hey Joel, Brad,

Can we backport these patches into 2.7 warrior, please?

c536e5f66af75f4301361363e37d7f4e3aa4eb37
ARM: dts: aspeed: vesnin: Add wdt2 with alt-boot option

6984ef32d05c2b5567f5d3f09d260ca7cbc2fc27
ARM: dts: aspeed: vesnin: Add secondary SPI flash chip

653aedbf02b71d6930959323e76961da98eab858
watchdog: aspeed: add support for dual boot

Thanks.