PCI: qcom: Drop unused post_deinit callback

Drop the unused and confusingly named post_deinit callback that was
added for the now removed pipe clock handling.

If ever needed we can add back a callback named pre_deinit (or perhaps
rather pre_phy_power_off) instead.

Link: https://lore.kernel.org/r/20220928155421.21660-2-johan+linaro@kernel.org


Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>