wifi: mwifiex: Convert to use jiffies macro

Use time_after macro instead of using jiffies directly to handle wraparound.
Change the type to to unsigned long to avoid unnecessary casts.

Signed-off-by: Chen Yufan <chenyufan@vivo.com>
Acked-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20240823070320.430753-1-chenyufan@vivo.com