Input: trackpoint - Optimize trackpoint init to use power-on reset

The trackpoint driver sets various parameter default values, all of
which happen to be power-on defaults (Source: IBM TrackPoint Engineering
Specification, Version 4.0. Also confirmed by empirical data).

By sending the power-on reset command to reset all parameters to
power-on state, we can skip the lengthy process of programming all
parameters. In testing, ~2.5 secs of time writing parameters was reduced
to .35 seconds waiting for power-on reset to complete.
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/trackpoint.h

@@ -126,6 +126,8 @@
 #define TP_DEF_PTSON		0x00
 #define TP_DEF_SKIPBACK		0x00
 #define TP_DEF_EXT_DEV		0x00	/* 0 means enabled */
+#define TP_DEF_TWOHAND		0x00
+#define TP_DEF_SOURCE_TAG	0x00
 
 #define MAKE_PS2_CMD(params, results, cmd) ((params<<12) | (results<<8) | (cmd))
 
@@ -136,9 +138,9 @@ struct trackpoint_data
 	unsigned char thresh, upthresh;
 	unsigned char ztime, jenks;
 
+	/* toggles */
 	unsigned char press_to_select;
 	unsigned char skipback;
-
 	unsigned char ext_dev;
 };