arm64: dts: intel: agilex5: Add simple-bus node on top of dma controller node

arm64: dts: intel: agilex5: Add simple-bus node on top of dma controller node

Move dma-controller node under simple-bus node to allow bus node specific
property able to be properly defined. This is require to fulfill Agilex5
bus limitation that is limited to 40-addressable-bit.

Update the compatible string for the DMA controller nodes in the Agilex5
device tree from the generic "snps,axi-dma-1.01a" to the platform-specific
"altr,agilex5-axi-dma". Add fallback capability to ensure driver is able
to initialize properly.

This change enables the use of platform-specific features and constraints
in the driver, such as setting a 40-bit DMA addressable mask through
dma-ranges, which is required for Agilex5. It also aligns with the updated
device tree bindings and driver support for this compatible string.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>