msm: pil-q6v5-mss: Don't fail ops if the modem is not loadable

Clients of PIL may still try to get the modem even if
it is not loaded by PIL (the modem is booted prior to
kernel bootup in these configurations). Don't fail the
corresponding ops, just return success.

CRs-Fixed: 422637
Change-Id: I7286f75f1baa94199f4a3aab91ef5e0b5b181270
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>