msm: camera: fix AXI RESET cmd field to be 32 byte

In 32 bit userspace and 64 bit kernel,
using long could cause the bit lenght difference in kernel and userspace.
change to use uint32_t instead of long.

Change-Id: I2f3d8f30074b444e2919b53ddb0247da5f97baa9
Signed-off-by: Peter Liu <pingchie@codeaurora.org>