msm: vidc: Allocate memory for response handler in probe

The response handler requires 95 KB of memory to handle
the firmware responses. This memory is allocated every
time the video driver downloads the firmware image.
If the device is running for a long time and we hit
firmware errors, then the firmware will be downloaded
several times. During this time, some video sessions
can fail because kmalloc might fail to allocate 95 KB
of contiguous memory, if the system memory is fragmented.
To overcome this problem, allocate the response handler
memory early on during probe, when the system memory is
still unfragmented.

Change-Id: I6c56eae75dca5c13c31eb1bd075f8903b236259a
Signed-off-by: Arun Menon <avmenon@codeaurora.org>