dt-bindings: timer: fsl,imxgpt: Document fsl,imx35-gpt

The i.MX35 General Purpose Timer is compatible with i.MX31.

Document the fsl,imx35-gpt compatible.

This fixes the following dt-schema warning:

timer@53f90000: compatible: 'oneOf' conditional failed, one must be fixed:
['fsl,imx35-gpt', 'fsl,imx31-gpt'] is too long
'fsl,imx1-gpt' was expected
'fsl,imx21-gpt' was expected
'fsl,imx27-gpt' was expected
'fsl,imx31-gpt' was expected
'fsl,imx35-gpt' is not one of ['fsl,imx25-gpt', 'fsl,imx50-gpt', 'fsl,imx51-gpt', 'fsl,imx53-gpt', 'fsl,imx6q-gpt']
'fsl,imx6dl-gpt' was expected
'fsl,imx35-gpt' is not one of ['fsl,imx6sl-gpt', 'fsl,imx6sx-gpt', 'fsl,imx8mp-gpt', 'fsl,imxrt1050-gpt', 'fsl,imxrt1170-gpt']
'fsl,imx35-gpt' is not one of ['fsl,imx6ul-gpt', 'fsl,imx7d-gpt']
'fsl,imx6sx-gpt' was expected

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20241202132147.587799-2-festevam@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>