dt-bindings: power: supply: cpcap-charger: update cpcap-charger.yaml reference

dt-bindings: power: supply: cpcap-charger: update cpcap-charger.yaml reference

Changeset ce49e4282200 ("dt-bindings: power: supply: cpcap-charger: Convert to DT schema format")
renamed: Documentation/devicetree/bindings/power/supply/cpcap-charger.txt
to: Documentation/devicetree/bindings/power/supply/cpcap-charger.yaml.

Update its cross-reference accordingly.

Fixes: ce49e4282200 ("dt-bindings: power: supply: cpcap-charger: Convert to DT schema format")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/e9ce216362b7b9dcf84d707a3854247123440bf7.1622648507.git.mchehab+huawei@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>