ARM: imx8m: Deduplicate CAAM init with arch_misc_init() call

Instead of duplicating code implemented by i.MX8M version of arch_misc_init()
in every board, enable CONFIG_ARCH_MISC_INIT and call arch_misc_init() from
spl_board_init(). This removes the duplication. No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/board/freescale/imx8mn_evk/spl.c b/board/freescale/imx8mn_evk/spl.c
index c0bfb67..380abec 100644
--- a/board/freescale/imx8mn_evk/spl.c
+++ b/board/freescale/imx8mn_evk/spl.c
@@ -49,11 +49,8 @@
 	struct udevice *dev;
 	int ret;
 
-	if (IS_ENABLED(CONFIG_FSL_CAAM)) {
-		ret = uclass_get_device_by_driver(UCLASS_MISC, DM_DRIVER_GET(caam_jr), &dev);
-		if (ret)
-			printf("Failed to initialize caam_jr: %d\n", ret);
-	}
+	arch_misc_init();
+
 	puts("Normal Boot\n");
 
 	ret = uclass_get_device_by_name(UCLASS_CLK,