staging: wilc1000: remove WILC_memcpy_INTERNAL

Remove WILC_memcpy_INTERNAL that is used in the WILC_memcpy
because WILC_memcpy is replaced by memcpy.

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