ipmi: bt-bmc: Add ast2500 compatible string

The ast2500 SoCs contain the same IPMI BT device.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>

Documentation/devicetree/bindings/ipmi/aspeed,ast2400-ibt-bmc.txt

@@ -6,7 +6,9 @@ perform in-band IPMI communication with their host.
 
 Required properties:
 
-- compatible : should be "aspeed,ast2400-ibt-bmc"
+- compatible : should be one of
+	"aspeed,ast2400-ibt-bmc"
+	"aspeed,ast2500-ibt-bmc"
 - reg: physical address and size of the registers
 
 Optional properties:

drivers/char/ipmi/bt-bmc.c

@@ -523,6 +523,7 @@ static int bt_bmc_remove(struct platform_device *pdev)
 
 static const struct of_device_id bt_bmc_match[] = {
 	{ .compatible = "aspeed,ast2400-ibt-bmc" },
+	{ .compatible = "aspeed,ast2500-ibt-bmc" },
 	{ },
 };