drivers: spi: dw: fix naming convention of aux-reg

aux-reg should be defined with a hyphen in the bindings

Signed-off-by: Ryan McClelland <ryanmcclelland@meta.com>

dts/arc/synopsys/emsdp.dtsi

@@ -135,7 +135,7 @@
 			interrupts = <63 2>, <64 2>, <65 2>;
 			interrupt-names = "err_int", "rx_avail", "tx_req";
 			interrupt-parent = <&intc>;
-			aux_reg;
+			aux-reg;
 			fifo-depth = <16>;
 		};
 
@@ -149,7 +149,7 @@
 			interrupts = <67 2>, <68 2>, <69 2>;
 			interrupt-names = "err_int", "rx_avail", "tx_req";
 			interrupt-parent = <&intc>;
-			aux_reg;
+			aux-reg;
 			fifo-depth = <16>;
 		};
 	};

dts/bindings/spi/snps,designware-spi.yaml

@@ -14,11 +14,11 @@ properties:
   interrupts:
     required: true
 
-  aux_reg:
+  aux-reg:
+    type: boolean
     description: |
       This value is used for auxiliary register access. For
       other platform, this value should be default 0.
-    type: boolean
 
   fifo-depth:
     type: int