dt-bindings: arm: update vexpress-config.yaml references

Changeset 7e8339b5 ("dt-bindings: arm: convert vexpress-config to DT schema")
renamed: Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
to: Documentation/devicetree/bindings/arm/vexpress-config.yaml.

Update the cross-references accordingly.

Fixes: 7e8339b5 ("dt-bindings: arm: convert vexpress-config to DT schema")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/7020edd9e183652249fc95bf61a1055cc342a4dc.1654529011.git.mchehab@kernel.org

Documentation/devicetree/bindings/hwmon/vexpress.txt

@@ -9,7 +9,7 @@ Requires node properties:
 	"arm,vexpress-power"
 	"arm,vexpress-energy"
 - "arm,vexpress-sysreg,func" when controlled via vexpress-sysreg
-  (see Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
+  (see Documentation/devicetree/bindings/arm/vexpress-config.yaml
   for more details)
 
 Optional node properties:

Documentation/devicetree/bindings/regulator/vexpress.txt

@@ -4,7 +4,7 @@ Versatile Express voltage regulators
 Requires node properties:
 - "compatible" value: "arm,vexpress-volt"
 - "arm,vexpress-sysreg,func" when controlled via vexpress-sysreg
-  (see Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
+  (see Documentation/devicetree/bindings/arm/vexpress-config.yaml
   for more details)
 
 Required regulator properties: