ARM: dts: aspeed: Add secure boot controller node
The ast2600 has a secure boot controller. Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com> Link: https://lore.kernel.org/r/20211117035106.321454-3-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>