staging/mei: mei.h defining user space interface

define IOCTL_MEI_CONNECT_CLIENT and its associated structure

When the user wants to connect to a ME feature/client after
it open a file descriptor to the driver, he need to use Connect
IOCTL.

This IOCTL received a struct that contains a union of 2 other structs.

1st struct - Input Parameters:
	UUID - a predefine unique that identify the ME feature, this
		 id per feature is constant all over the chipsets
		 and versions.

2nd struct Output Parameters:
	MaxMessageLen - 	maximum message length that allowed
				to be send to the feature
	ProtocolVersion ME feature current protocol version.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Itzhak Tzeel-Krupp <itzhak.tzeel-krupp@intel.com>
Signed-off-by: Oren Weil <oren.jer.weil@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>