On am437x-gp-evm, pixcir_i2c_ts can wakeup the system from low power
state via pinctrl and IO daisy chain using generic wakeirq framework.
With commit 
3fffd1283927 ("i2c: allow specifying separate wakeup
interrupt in device tree") i2c core allows optional wakeirq to be
specified via device tree. Add wakeup irq entry to enable pixcir_i2c_ts
to wake the system from low power state.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
 
                attb-gpio = <&gpio3 22 GPIO_ACTIVE_HIGH>;
 
+               /*
+                * 0x264 represents the offset of padconf register of
+                * gpio3_22 from am43xx_pinmux base.
+                */
+               interrupts-extended = <&gpio3 22 IRQ_TYPE_NONE>,
+                                     <&am43xx_pinmux 0x264>;
+               interrupt-names = "tsc", "wakeup";
+
                touchscreen-size-x = <1024>;
                touchscreen-size-y = <600>;
+               wakeup-source;
        };
 
        ov2659@30 {