Clean up ARM_TP_ADDRESS and RAS location

[Rafal Jaworowski]

Hi,

The following patch de-hardcodes usage of ARM_TP_ADDRESS and RAS local
storage, it also moves this special purpose page to a more convenient place
i.e. after the vectors high page, more towards the end of address space.
Previous location (0xe000_0000) caused grief if KVA where to go beyond the
default limit.

http://people.freebsd.org/~raj/patches/arm/cleanup_tp_ras.diff

Let me hear your comments.

Rafal