mwifiex: uninit wakeup info when removing device

We manually init wakeup info, but we don't detach it on device removal.
This means that if we (for example) rmmod + modprobe the driver, the
device framework might return -EEXIST the second time, and we'll
complain in the logs:

[  839.311881] mwifiex_pcie 0000:01:00.0: fail to init wakeup for mwifiex

AFAICT, there's no other negative effect.

But we can fix this by disabling wakeup on remove, similar to what a few
other drivers do (e.g., the power supply framework).

This code (and bug) has existed on SDIO for a while, but it got moved
around and enabled for PCIe with commit 853402a0 ("mwifiex: Enable
WoWLAN for both sdio and pcie").

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>