staging: wilc1000: remove the mutliple #define used for same macro

Moved the same #define in common header file instead of having their
declartion in different files.

Below macros are moved to header file:
TCP_ACK_FILTER_LINK_SPEED_THRESH
DEFAULT_LINK_SPEED
GET_PKT_OFFSET

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>