realtek: create separate Kconfig file

Add new a Kconfig file and a vendor config for realtek. Also update MAINTAINERS
which we missed to do when earlier moving rtlwifi.

Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig
index c92671f..28af8b1 100644
--- a/drivers/net/wireless/Kconfig
+++ b/drivers/net/wireless/Kconfig
@@ -24,6 +24,7 @@
 source "drivers/net/wireless/intel/Kconfig"
 source "drivers/net/wireless/intersil/Kconfig"
 source "drivers/net/wireless/marvell/Kconfig"
+source "drivers/net/wireless/realtek/Kconfig"
 source "drivers/net/wireless/st/Kconfig"
 source "drivers/net/wireless/zydas/Kconfig"
 
@@ -81,8 +82,6 @@
 
 	  If you choose to build a module, it'll be called rndis_wlan.
 
-source "drivers/net/wireless/realtek/rtl818x/Kconfig"
-
 config MAC80211_HWSIM
 	tristate "Simulated radio testing tool for mac80211"
 	depends on MAC80211
@@ -99,8 +98,6 @@
 source "drivers/net/wireless/ath/Kconfig"
 source "drivers/net/wireless/rt2x00/Kconfig"
 source "drivers/net/wireless/mediatek/Kconfig"
-source "drivers/net/wireless/realtek/rtlwifi/Kconfig"
-source "drivers/net/wireless/realtek/rtl8xxxu/Kconfig"
 source "drivers/net/wireless/ti/Kconfig"
 source "drivers/net/wireless/rsi/Kconfig"