ath11k: add static window support for register access

Three window slots can be configure. First window slot
dedicate for dynamic selection and remaining two slots
dedicate for static selection. To optimise the window
selection, frequent registers (UMAC, CE) are configure
in static window slot. so that we minimise the window
selection. Other registers are configure in dynamic window
slot. Get the window start address from the respective
offset and access the read/write register.

Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.4.0.1.r2-00012-QCAHKSWPL_SILICONZ-1

Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Anilkumar Kolli <akolli@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1612946530-28504-7-git-send-email-akolli@codeaurora.org