soc: qcom: scm_qcpe: Derive HAB id from HAB vmid dt node

Derive the QCPE HAB id from the HAB vmid DTS node, rather
than have it hard coded into the driver.

Change-Id: I29ec7647890f8bc194d31f0402c5ed314572462f
Signed-off-by: Amit Blay <ablay@codeaurora.org>