soc: qcom: dfc: Allocate the query grant structures on heap

The allocation of query structures on stack causes errors
similar to the following -

338.909652:   <6> Kernel panic - not syncing: stack-protector:
 Kernel stack is corrupted in: ffffff8395993d70
338.909671:   <6> Workqueue: rmnet_powersave_work qmi_rmnet_check_stats
338.909674:   <2> Call trace:
338.909679:   <2>  dump_backtrace+0x0/0x138
338.909681:   <2>  show_stack+0x18/0x20
338.909686:   <2>  dump_stack+0xc4/0x100
338.909688:   <2>  panic+0x1dc/0xa08
338.909690:   <2>  trace_raw_output_user_fault+0x0/0x60
338.909692:   <2>  dfc_do_burst_flow_control+0x0/0x448
338.909694:   <2>  qmi_rmnet_check_stats+0x90/0x260
338.909696:   <2>  process_one_work+0x1f4/0x458
338.909698:   <2>  worker_thread+0x2f0/0x458
338.909701:   <2>  kthread+0x110/0x120
338.909703:   <2>  ret_from_fork+0x10/0x18

CRs-Fixed: 2345758
Change-Id: I8333769ef6a74297d63e3474f68d4613342c4441
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>