Input: wacom - relax Bamboo stylus ID check

commit c5981411 upstream.

Bit 0x02 always means tip versus eraser. Bit 0x01 is something related
to version of stylus and different values are starting to be used.

Relaxing proximity check is required to be used with 3rd generation
Bamboo Pen and Touch tablets.
Signed-off-by: Chris Bagwell <chris@cnpbagwell.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/input/tablet/wacom_wac.c

@@ -843,12 +843,7 @@ static int wacom_bpt_pen(struct wacom_wac *wacom)
 	unsigned char *data = wacom->data;
 	int prox = 0, x = 0, y = 0, p = 0, d = 0, pen = 0, btn1 = 0, btn2 = 0;
 
-	/*
-	 * Similar to Graphire protocol, data[1] & 0x20 is proximity and
-	 * data[1] & 0x18 is tool ID.  0x30 is safety check to ignore
-	 * 2 unused tool ID's.
-	 */
-	prox = (data[1] & 0x30) == 0x30;
+	prox = (data[1] & 0x20) == 0x20;
 
 	/*
 	 * All reports shared between PEN and RUBBER tool must be