drivers: mspi: changes made as mentioned by Muhammed Asif

1- Moved microchip,qspi-g1-mspi.yaml from dts\bindings\arm
to dts\bindings\mspi folder.
2- Moved clock and pin control config in init function.
3- Removed required: false instances.
4- Used DT Macro to fetch max qspi controller frequency.

Signed-off-by: Shikhar Tandon <Shikhar.Tandon@microchip.com>

Author: shikhartandonmicrochip

boards/microchip/sam/sam_e54_xpro/sam_e54_xpro.dts

@@ -254,7 +254,7 @@
 
     /* Optional child if you actually wired a NOR to the QSPI signals */
     mspi_flash0: mspi_flash0@0 {
-        compatible = "microchip,qspi-g1-mspi-flash", "jedec,mspi-nor";
+        compatible = "microchip,qspi-g1-mspi-flash","jedec,mspi-nor";
         reg = <0>;                     /* HW CS#0 on SAME54 */
         mspi-max-frequency = <59000000>; /*59 MHz max in Single Data Rate,54Mhz in DDR*/