qtnfmac_pcie: Use module_pci_driver

Use module_pci_driver for drivers whose init and exit functions
only register and unregister, respectively.

Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201221075735.197255-1-ameynarkhede03@gmail.com