pwm: Add STM32 LPTimer PWM driver

Add support for single PWM channel on Low-Power Timer, that can be
found on some STM32 platforms.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 313c107..7cb982b 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -417,6 +417,16 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-stm32.
 
+config PWM_STM32_LP
+	tristate "STMicroelectronics STM32 PWM LP"
+	depends on MFD_STM32_LPTIMER || COMPILE_TEST
+	help
+	  Generic PWM framework driver for STMicroelectronics STM32 SoCs
+	  with Low-Power Timer (LPTIM).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-stm32-lp.
+
 config PWM_STMPE
 	bool "STMPE expander PWM export"
 	depends on MFD_STMPE