drm: Rename device to dev in struct drm_device

Reducing differences with Linux
drm: Sync a few headers with Linux 3.8
serializer.9: Mention LWKT_SERIALIZE_INITIALIZER
atomic/i386: Update intr_cond comment
acpi/cstate: Use serializer to protect _CST notfication and sysctls
acpi/cstate: Minor style cleanup
drm: Import linux/err.h from FreeBSD's OFED stack