On QCA6390 reg_start and reg_size values are different from IPQ8074 so we need
to change the values runtime. As we can't modify a static const variable
hw_srng_config directly, instead use it as a template, copy it and modify the
copy with correct values.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.1.0.1-01238-QCAHKSWPL_SILICONZ-2
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1597389030-13887-12-git-send-email-kvalo@codeaurora.org