pmem: volatile bindings for the poorly enabled
pmem: volatile bindings for the poorly enabled

PMEM_DISK bindings were added, but they rely on a rather
recent mmap feature. This patch steals from those bindings
to add volatile bindings. I've used these bindings with
PMEM_VOLATILE to launch an instance with the publicly
available systemsim-p9. The bindings are volatile and one
should not expect any data to be saved/retrieved.

Signed-off-by: Balbir singh <ac7b77b73f9d2cc0faddd296218dde0558e170e3@gmail.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

qemu/skiboot,stewart-ibm/skiboot,stewart-ibm/skiboot,open-power/skiboot,legoater/skiboot,qemu/skiboot,open-power/skiboot,qemu/skiboot,open-power/skiboot,shenki/skiboot,stewart-ibm/skiboot,legoater/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,legoater/skiboot,legoater/skiboot,open-power/skiboot,legoater/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,shenki/skiboot