dt-bindings: pinctrl: aspeed: Fix 'compatible' schema errors

The Aspeed pinctl schema have errors in the 'compatible' schema:

Documentation/devicetree/bindings/pinctrl/aspeed,ast2400-pinctrl.yaml: \
properties:compatible:enum: ['aspeed', 'ast2400-pinctrl', 'aspeed', 'g4-pinctrl'] has non-unique elements
Documentation/devicetree/bindings/pinctrl/aspeed,ast2500-pinctrl.yaml: \
properties:compatible:enum: ['aspeed', 'ast2500-pinctrl', 'aspeed', 'g5-pinctrl'] has non-unique elements

Flow style sequences have to be quoted if the vales contain ','. Fix
this by using the more common one line per entry formatting.

Fixes: 0a617de1 ("dt-bindings: pinctrl: aspeed: Convert AST2500 bindings to json-schema")
Fixes: 07457937 ("dt-bindings: pinctrl: aspeed: Convert AST2400 bindings to json-schema")
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Joel Stanley <joel@jms.id.au>
Cc: linux-aspeed@lists.ozlabs.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Rob Herring <robh@kernel.org>