core: arm: use fdt64_ld() to read possibly unaligned kaslr-seed

Read possibly unaligned kaslr-seed using `fdt64_ld()`
to avoid ubsan panic while booting with `CFG_CORE_ASLR=y`

Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Abhishek Revadekar <abhishek.rvdkr@yahoo.com>

core/arch/arm/kernel/boot.c

@@ -1508,7 +1508,7 @@ unsigned long __weak get_aslr_seed(void)
 		goto err;
 	}
 
-	return fdt64_to_cpu(*seed);
+	return fdt64_to_cpu(fdt64_ld(seed));
 
 err:
 	/* Try platform implementation */