ARM: imx_v4_v5_defconfig: enable PWM driver

While there is no mainline board that makes use of the PWM still enable the
driver for it to increase compile test coverage.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/configs/imx_v4_v5_defconfig

@@ -170,6 +170,9 @@ CONFIG_IMX_SDMA=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_IIO=y
 CONFIG_FSL_MX25_ADC=y
+CONFIG_PWM=y
+CONFIG_PWM_IMX1=y
+CONFIG_PWM_IMX27=y
 CONFIG_EXT4_FS=y
 # CONFIG_DNOTIFY is not set
 CONFIG_VFAT_FS=y