power: smb5: Expose QNOVO_ENABLE property

Currently, QNOVO is not enabled and hence QNOVO_ENABLE property
is not exposed. However, there are clients (like FG) which can
attempt reading this property and the absence of it creates a log
spew. Fix it by returning 0 through QNOVO_ENABLE property.

Change-Id: Ib9ff11779a62bf49091524a114d346c7bea7d5ec
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>