Revert "ath10k: fix DMA related firmware crashes on multiple devices"

This reverts commit 76d164f5.
PCIe hung issue was observed on multiple platforms. The issue was reproduced
when DUT was configured as AP and associated with 50+ STAs.

For QCA9984/QCA9888, the DMA_BURST_SIZE register controls the AXI burst size
of the RD/WR access to the HOST MEM.
0 - No split , RAW read/write transfer size from MAC is put out on bus
    as burst length
1 - Split at 256 byte boundary
2,3 - Reserved

With PCIe protocol analyzer, we can see DMA Read crossing 4KB boundary when
issue happened. It broke PCIe spec and caused PCIe stuck. So revert
the default value from 0 to 1.

Tested:  IPQ8064 + QCA9984 with firmware 10.4-3.10-00047
         QCS404 + QCA9984 with firmware 10.4-3.9.0.2--00044
         Synaptics AS370 + QCA9888  with firmware 10.4-3.9.0.2--00040

Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>