media: venus: hfi: Add 6xx AXI halt logic

This patch takes the downstream AXI halt routine and applies it when
IS_V6() is true.

bod: Converted to readl_poll_timeout()
     Converted LPI update timeout to dev_dbg. In practice this register
     never appears to update with the value 0x07. Discussing with contacts
     in qcom video team, this toggle only pertains to low-power mode.
     Keeping the write for the sake of fidelity with downstream.

Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org>
Co-developed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>