fs/dcache: remove __read_mostly and increase suspend cache pressure to 50

Change-Id: Ibfb0ca05f7c6deb4c82fb8a267e15fd35d621e8f
Revert "arm: adapt upstream updates and current kernel for each other"

This reverts commit 9dbd3c048b6c9b9c7afbc348aa1859bf9362aa3a.
Revert "upstream to linux 3.0.101"

This reverts commit ed5e57efd601e3ed9074e3180e3a4916fb8ff03e.