ARM: Add a fake flash controller so that unmodified linux can boot
ARM: Add a fake flash controller so that unmodified linux can boot

With this change an unmodified Linux kernel can boot in M5.

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin