haven: Add support for the MEM_QCOM_LOOKUP_SGL call

The MEM_QCOM_LOOKUP_SGL RM call is required to retrieve
handles for memparcels created through hyp assign. Thus,
add support for it in the RM driver.

Change-Id: Ib854187daffa13a44c948111ef560c3479f2590c
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>