sandbox: Align linker lists to a 32-byte boundary

Use this larger boundary to ensure that linker lists at least start on the
maximum possible alignment boundary. See also the CONFIG_LINKER_LIST_ALIGN
setting, but that is host-arch-specific, so it seems better to use the
largest value for every host architecture.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/sandbox/cpu/u-boot-spl.lds

@@ -8,7 +8,7 @@
 SECTIONS
 {
 
-	. = ALIGN(4);
+	. = ALIGN(32);
 	.u_boot_list : {
 		KEEP(*(SORT(.u_boot_list*)));
 	}

arch/sandbox/cpu/u-boot.lds

@@ -8,7 +8,7 @@
 SECTIONS
 {
 
-	. = ALIGN(4);
+	. = ALIGN(32);
 	.u_boot_list : {
 		KEEP(*(SORT(.u_boot_list*)));
 	}