staging: wilc1000: remove wilc_platform include file

This patch removes wilc_platform.h include file in wilc_oswrapper.h
wilc_platform.h have several standard header files so that some header
files should be included to avoid compilation errors.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>