dt-bindings: ipmi: bt-bmc: add 'clocks' as a required property

If LPC BT driver is registered ahead of lpc-ctrl module, LPC BT
hardware block will be enabled without heart beating of LCLK until
lpc-ctrl enables the LCLK. This issue causes improper handling on
host interrupts when the host sends interrupts in that time frame.
Then kernel eventually forcibly disables the interrupt with
dumping stack and printing a 'nobody cared this irq' message out.

To prevent this issue, all LPC sub drivers should enable LCLK
individually so this patch adds 'clocks' property as one of
required properties to enable the LCLK by the LPC IBT driver.

Note: dtsi change in this patch series should be applied along with,
and dtbs should be re-compiled after applying this series since
it's adding a new required property otherwise the driver will not
be probed correctly.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211108190200.290957-3-jae.hyun.yoo@intel.com
Signed-off-by: Joel Stanley <joel@jms.id.au>

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

@@ -11,6 +11,7 @@ Required properties:
 	"aspeed,ast2500-ibt-bmc"
 	"aspeed,ast2600-ibt-bmc"
 - reg: physical address and size of the registers
+- clocks: clock for the device
 
 Optional properties:
 
@@ -23,4 +24,5 @@ Example:
 		compatible = "aspeed,ast2400-ibt-bmc";
 		reg = <0x1e789140 0x18>;
 		interrupts = <8>;
+		clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
 	};