msm: vidc: Stub out Q6 device if APR isn't present

If APR isn't present, the Q6 HFI fails to compile.  Stub out the
functions instead of mucking about in the Makefile and adding extra
defines to prevent compilation.

Change-Id: Ia3d6aab7dc1b1a87a365ea880405488ce3fac725
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>