configs/orangepi-pc-plus: enable WiFi support

Make WiFi work out of the box on orangepi-pc-plus:
  - add rtl8xx firmware
  - add rtl8189fs driver
  - add mdev for module autoloading

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

configs/orangepi_pc_plus_defconfig

@@ -1,6 +1,7 @@
 BR2_arm=y
 BR2_cortex_a7=y
 BR2_ARM_FPU_VFPV4=y
+BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV=y
 BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_13=y
 BR2_TARGET_GENERIC_HOSTNAME="OrangePi_PC_Plus"
 BR2_TARGET_GENERIC_ISSUE="Welcome to Buildroot for the Orange Pi PC Plus"
@@ -29,6 +30,11 @@ BR2_PACKAGE_HOST_GENIMAGE=y
 BR2_PACKAGE_HOST_MTOOLS=y
 BR2_PACKAGE_HOST_UBOOT_TOOLS=y
 
+# wireless driver and firmware
+BR2_PACKAGE_RTL8189FS=y
+BR2_PACKAGE_LINUX_FIRMWARE=y
+BR2_PACKAGE_LINUX_FIRMWARE_RTL_81XX=y
+
 # wireless tools
 BR2_PACKAGE_IW=y
 BR2_PACKAGE_WIRELESS_TOOLS=y