ath11k: enable shadow register configuration and access

To enable shadow register access, host needs to pass shadow
register configuration to firmware via qmi message. Host also
needs to update ring's HP or TP address to shadow register
address. The write operation to shadow register will be
forwarded to target register by hardware automatically, and
the write operation to shadow register is permitted even
when the target is in power save or sleep mode.

Update the shadow config whenever power up happens.

This feature is controlled by hw parameter supports_shadow_regs which is only
enabled for QCA6390.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1601544890-13450-3-git-send-email-kvalo@codeaurora.org