tegra: pwm: Add a driver for the tegra PWM

This PWM supports four channels. The driver always uses the 32KHz clock,
and adjusts the duty cycle accordingly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index b6d8c16..fd414b1 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -13,3 +13,6 @@
 obj-$(CONFIG_DM_PWM) += pwm-uclass.o
 obj-$(CONFIG_PWM_ROCKCHIP) += rk_pwm.o
 obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o
+ifdef CONFIG_DM_PWM
+obj-$(CONFIG_PWM_TEGRA) += tegra_pwm.o
+endif