ath11k: qmi: try to allocate a big block of DMA memory first

Not all firmware versions support allocating DMA memory in smaller blocks so
first try to allocate big block of DMA memory for QMI. If the allocation fails,
let firmware request multiple blocks of DMA memory with smaller size.

This also fixes an unnecessary error message seen during ath11k probe on
QCA6390:

ath11k_pci 0000:06:00.0: Respond mem req failed, result: 1, err: 0
ath11k_pci 0000:06:00.0: qmi failed to respond fw mem req:-22

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1608127593-15192-1-git-send-email-kvalo@codeaurora.org