staging: wilc1000: remove unused argument of chip_sleep_manually function

This patch removes u32SleepTime that is second argument of
chip_sleep_manually function because it is not used in this function.
Remove argument in the function call also.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>