riscv: defconfig: Enable PWM support for SpacemiT K1 SoC

Enable CONFIG_PWM and CONFIG_PWM_PXA in the defconfig
to support the PWM controller used on the SpacemiT K1 SoC.

Signed-off-by: Guodong Xu <guodong@riscstar.com>
Reviewed-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

Author: docularxu

arch/riscv/configs/defconfig

@@ -257,6 +257,8 @@ CONFIG_RPMSG_CTRL=y
 CONFIG_RPMSG_VIRTIO=y
 CONFIG_PM_DEVFREQ=y
 CONFIG_IIO=y
+CONFIG_PWM=y
+CONFIG_PWM_PXA=m
 CONFIG_THEAD_C900_ACLINT_SSWI=y
 CONFIG_PHY_SUN4I_USB=m
 CONFIG_PHY_STARFIVE_JH7110_DPHY_RX=m