dts: bindings: correct information in mcux edma bindings

With the current implementation, the 1st cell is not DMAMUX id
as mentioned in the bindings (0 for DMAMUX0 and 1 for DMAMUX1).

Moreover, the referenced Linux bindings is obsoleted, it was
migrated to use yaml syntax

Signed-off-by: Dat Nguyen Duy <dat.nguyenduy@nxp.com>

dts/bindings/dma/nxp,mcux-edma.yaml

@@ -10,6 +10,9 @@ include: dma-controller.yaml
 properties:
   reg:
     required: true
+    description: |
+      Specifies base physical address(s) and size of DMA and respective DMAMUX register(s)
+      that routes DMA sources
 
   interrupts:
     required: true
@@ -33,21 +36,10 @@ properties:
     required: true
     description: Number of items to expect in a DMAMUX specifier
 
-# Parameter syntax of NXP follows the dmamux client dts syntax
-# in the Linux kernel declared in
-# https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git/tree/Bindings/dma/fsl-edma.txt
-#
 # - #dma-cells : Must be <2>.
-#  The 1st cell specifies the DMAMUX(0 for DMAMUX0 and 1 for DMAMUX1).
-#    Specific request source can only be multiplexed by specific channels
-#    group called DMAMUX.
-#  The 2nd cell specifies the request source(slot) ID.
+#  The 1st cell specifies the DMA channel which will be used
+#  The 2nd cell specifies the request source (slot) ID.
 #    See the SoC's reference manual for all the supported request sources.
-# * DMA clients
-# DMA client drivers that uses the DMA function must use the format described
-# in the dma.txt file, using a two-cell specifier for each channel: the 1st
-# specifies the channel group(DMAMUX) in which this request can be multiplexed,
-# and the 2nd specifies the request source.
 
 dma-cells:
   - mux