ath11k: ce: support different CE configurations

QCA6390 uses only 9 Copy Engines while IPQ8074 may use 12, make it possible to
change CE configuration dynamically via hw_params.

The defines for host_ce_config_wlan and CE_COUNT are temporary solutions, they
will be removed in the following patches to keep things simple.

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: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1597576599-8857-4-git-send-email-kvalo@codeaurora.org