boards: silabs: sim3u1xx_dk: Enable crypto support

Using the HW acceleration is much faster than either Mbed TLS or
tinycrypt.

Signed-off-by: Reto Schneider <reto.schneider@husqvarnagroup.com>

boards/silabs/dev_kits/sim3u1xx_dk/doc/index.rst

@@ -49,6 +49,8 @@ The board configuration supports the following hardware features:
 +-----------+------------+-------------------------------------+
 | SYSTICK   | on-chip    | systick                             |
 +-----------+------------+-------------------------------------+
+| AES       | on-chip    | crypto                              |
++-----------+------------+-------------------------------------+
 | DMA       | on-chip    | dma                                 |
 +-----------+------------+-------------------------------------+
 | FLASH     | on-chip    | flash memory                        |

boards/silabs/dev_kits/sim3u1xx_dk/sim3u1xx_dk.dts

@@ -109,3 +109,12 @@
 		};
 	};
 };
+
+&dma {
+	status = "okay";
+	dma-channels = <8>; /* Crypto DMA channels have ID 5, 6, and 7 */
+};
+
+&crypto {
+	status = "okay";
+};

boards/silabs/dev_kits/sim3u1xx_dk/sim3u1xx_dk.yaml

@@ -13,6 +13,7 @@ toolchain:
   - xtools
   - zephyr
 supported:
+  - crypto
   - dma
   - flash
   - gpio