ext qmsi: Make QMSI headers available to more than just drivers

QMSI provides more than just peripheral drivers, and it may be used
from the SOC or by applications that need finer grained control of the
platform.
This also makes the QMSI HAL consistent with the others.

Change-Id: I27490c98ccf1c1afcc090ce1e65f0e066eddc777
Signed-off-by: Iván Briano <ivan.briano@intel.com>