staging: wilc1000: rename u32SetCfgFlag of struct cfg_param_val

This patch renames u32SetCfgFlag of struct cfg_param_val to flag to
avoid CamelCase naming convention.

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