mwifiex: Drop unnecessary include pcieport_if.h

This header file is only needed for drivers binding to a PCI bridge
device allocated by drivers/pci/pcie/portdrv_core.c. The mwifiex driver
doesn't do that nor use any symbols defined in pcieport_if.h.

Cc: Amitkumar Karwar <akarwar@marvell.com>
Cc: Nishant Sarmukadam <nishants@marvell.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>