dt-bindings: fsl: convert m4if.txt and tigerp.txt to yaml format

dt-bindings: fsl: convert m4if.txt and tigerp.txt to yaml format

Convert m4if.txt and tigerp.txt to yaml format. These just use reg to
indicate memory region.

Additional changes:
- Add compatible string fsl,imx51-aipstz.
- Add fsl,imx53-tigerp and fail back to fsl,imx51-tigerp
- Add compatible string fsl,imx7d-pcie-phy, which is not real phy and just
indicate a memory region.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250417150608.3569512-1-Frank.Li@nxp.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>