accel/qaic: kcalloc + kzalloc to kzalloc

accel/qaic: kcalloc + kzalloc to kzalloc

Consolidate the two-element allocation into a single allocation using a
flexible array member. This reduces memory fragmentation and simplifies
the error path by eliminating the need to check for allocation failure
between the two allocations.

Add __counted_by for runtime bounds checking.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Tested-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://patch.msgid.link/20260401220643.12802-1-rosenp@gmail.com