staging: wilc1000: remove typedef from tstrWILC_WFIDrv

This patch removes typedef from the struct tstrWILC_WFIDrv and
rename it to host_if_drv.
This patch includes the removal of the comment for tstrWILC_WFIDrv as well.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>