common: add blkcache init

On m68k, block_cache list is relocated, but next and prev list
pointers are not adjusted to the relocated struct list_head address,
so the first iteration over the block_cache list hangs.

This patch initializes the block_cache list after relocation.

Signed-off-by: Angelo Durgehello <angelo.dureghello@timesys.com>
Reviewed-by: Eric Nelson <eric@nelint.com>

common/board_r.c

@@ -864,6 +864,9 @@ static init_fnc_t init_sequence_r[] = {
 #endif
 #if defined(CONFIG_PRAM)
 	initr_mem,
+#endif
+#ifdef CONFIG_BLOCK_CACHE
+	blkcache_init,
 #endif
 	run_main_loop,
 };