pwm: Add PWM driver for SAMA5D2

Add support for the PWM found on the SAMA5D2 family of devices.

Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 10d244b..55f2bc0 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -10,6 +10,7 @@
 
 obj-$(CONFIG_DM_PWM)		+= pwm-uclass.o
 
+obj-$(CONFIG_PWM_AT91)		+= pwm-at91.o
 obj-$(CONFIG_PWM_CROS_EC)	+= cros_ec_pwm.o
 obj-$(CONFIG_PWM_EXYNOS)	+= exynos_pwm.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o pwm-imx-util.o