IB/core: Add extended device capability flags

Since all the uverbs device_cap_flags are occupied, we need a place to
expose more device capabilities.

This patch adds a new 64 bit device_cap_flags_ex to expose new
device capabilities.

The lower 32 bits will be identical to the original device_cap_flags,
The upper 32 bits will be new capabilities.

Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>