riscv: defconfig: enable gpio support for HiFive Unleashed

Ethernet phy VSC8541-01 on HiFive Unleashed has its reset line
connected to a gpio, so enable GPIO driver's required to reset
the phy.

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Author: sagsifive

arch/riscv/configs/defconfig

@@ -64,6 +64,8 @@ CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
 CONFIG_SPI_SIFIVE=y
+CONFIG_GPIOLIB=y
+CONFIG_GPIO_SIFIVE=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_POWER_RESET=y
 CONFIG_DRM=y