dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

dt-bindings: dma: snps,dw-axi-dmac: Add compatible string for Agilex5

The address bus on Agilex5 is limited to 40 bits. When SMMU is enable this
will cause address truncation and translation faults. Hence introducing
"altr,agilex5-axi-dma" to enable platform specific configuration to
configure the dma addressable bit mask.

Add a fallback capability for the compatible property to allow driver to
probe and initialize with a newly added compatible string without requiring
additional entry in the driver.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/dbc775f114445c06c6e4ce424333e1f3cbb92583.1766966955.git.khairul.anuar.romli@altera.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>