ath10k: correct the length of DRAM dump for QCA6174 hw3.x/QCA9377 hw1.1

The length of DRAM dump for QCA6174 hw3.0/hw3.2 and QCA9377 hw1.1
are less than the actual value, some coredump contents are missed.
To fix it, change the length from 0x90000 to 0xa8000.

Fixes: 703f261d ("ath10k: add memory dump support for QCA6174/QCA9377")
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>