MAINTAINERS: update ti,sci.yaml reference

Changeset 5a9652f6 ("dt-bindings: arm: keystone: Convert ti,sci to json schema")
renamed: Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
to: Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml.

Update its cross-reference accordingly.

Fixes: 5a9652f6 ("dt-bindings: arm: keystone: Convert ti,sci to json schema")
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/6c9959f9d744b27908ff21a8414dcc772a45354f.1634630486.git.mchehab+huawei@kernel.org

MAINTAINERS

@@ -18514,7 +18514,7 @@ M:	Santosh Shilimkar <ssantosh@kernel.org>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	Documentation/devicetree/bindings/arm/keystone/ti,k3-sci-common.yaml
-F:	Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
+F:	Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
 F:	Documentation/devicetree/bindings/clock/ti,sci-clk.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/ti,sci-inta.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.yaml