riscv: defconfig: Update the defconfig

Update the defconfig:
 - Add CONFIG_HW_RANDOM=y and CONFIG_HW_RANDOM_VIRTIO=y to enable
   VirtIORNG when running on QEMU
Signed-off-by: NAlistair Francis <alistair.francis@wdc.com>
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>

arch/riscv/configs/defconfig

@@ -54,6 +54,8 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
 CONFIG_HVC_RISCV_SBI=y
+CONFIG_HW_RANDOM=y
+CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
 CONFIG_SPI_SIFIVE=y
 # CONFIG_PTP_1588_CLOCK is not set