Input: psmouse - use IS_ENABLED instead of homegrown code

Instead of having various protocols provide <protocol>_supported()
functions, let's use IS_ENABLED() macro that works well in "if" statements.

Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 68469fe..4ccd01d 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -727,7 +727,7 @@
 	if (psmouse_do_detect(focaltech_detect, psmouse, set_properties) == 0) {
 		if (max_proto > PSMOUSE_IMEX) {
 			if (!set_properties || focaltech_init(psmouse) == 0) {
-				if (focaltech_supported())
+				if (IS_ENABLED(CONFIG_MOUSE_PS2_FOCALTECH))
 					return PSMOUSE_FOCALTECH;
 				/*
 				 * Note that we need to also restrict
@@ -776,7 +776,7 @@
  * Try activating protocol, but check if support is enabled first, since
  * we try detecting Synaptics even when protocol is disabled.
  */
-			if (synaptics_supported() &&
+			if (IS_ENABLED(CONFIG_MOUSE_PS2_SYNAPTICS) &&
 			    (!set_properties || synaptics_init(psmouse) == 0)) {
 				return PSMOUSE_SYNAPTICS;
 			}
@@ -801,7 +801,7 @@
  */
 	if (max_proto > PSMOUSE_IMEX &&
 			cypress_detect(psmouse, set_properties) == 0) {
-		if (cypress_supported()) {
+		if (IS_ENABLED(CONFIG_MOUSE_PS2_CYPRESS)) {
 			if (cypress_init(psmouse) == 0)
 				return PSMOUSE_CYPRESS;