ARM: dts: add dm816x pwm property to timers

Adds ti,timer-pwm property to timers 4 to 7 to permit usage of their
PWM output fonctionnality via the dmtimer driver.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dm816x.dtsi

@@ -319,6 +319,7 @@ timer4: timer@48044000 {
 			reg = <0x48044000 0x2000>;
 			interrupts = <92>;
 			ti,hwmods = "timer4";
+			ti,timer-pwm;
 		};
 
 		timer5: timer@48046000 {
@@ -326,6 +327,7 @@ timer5: timer@48046000 {
 			reg = <0x48046000 0x2000>;
 			interrupts = <93>;
 			ti,hwmods = "timer5";
+			ti,timer-pwm;
 		};
 
 		timer6: timer@48048000 {
@@ -333,6 +335,7 @@ timer6: timer@48048000 {
 			reg = <0x48048000 0x2000>;
 			interrupts = <94>;
 			ti,hwmods = "timer6";
+			ti,timer-pwm;
 		};
 
 		timer7: timer@4804a000 {
@@ -340,6 +343,7 @@ timer7: timer@4804a000 {
 			reg = <0x4804a000 0x2000>;
 			interrupts = <95>;
 			ti,hwmods = "timer7";
+			ti,timer-pwm;
 		};
 
 		uart1: uart@48020000 {