haven: irq_lend: Defer vm_name to vmid translation

Presently, hh_irq_wait_for_lend translates supplied vm_name to vmid.
However, if this function is called prior to RM populating this table,
then wait_for_lend call fails with -EINVAL. Translating vm_name to vmid
in wait_for_lend is unnecessary, and only done because it was convenient
in private data structure. Thus, add vm_name to the private data
structure and translate vm_names upon receiving a lend notification.

Change-Id: Iaa51aaab42508ffa121a550afa0568a048327dca
Signed-off-by: Elliot Berman <eberman@codeaurora.org>