powerpc/powernv/vas: Define macros, register fields and structures

powerpc/powernv/vas: Define macros, register fields and structures

BugLink: http://bugs.launchpad.net/bugs/1718293
Define macros for the VAS hardware registers and bit-fields as well
as couple of data structures needed by the VAS driver.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[mpe: Fixup include guard to use _ASM_POWERPC_VAS_H]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 967689141eb37c4365eac0fac82d857773098475)
Signed-off-by: Gustavo Walbon <gwalbon@linux.vnet.ibm.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>