ARM: dts: imx6sx-sdb-reva: Add revision in board compatible string
i.MX6SX SDB Rev-A board should use its own board compatible
string instead of default i.MX6SX SDB board.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
authored by