wifi: esp32: remove unused ESP32_WIFI_{SSID,PSK}

Those Kconfig options are no longer used after ESP32 WiFi driver was
converted to Zephyr WiFi mgmt and the removal of platform specific
`samples/boards/esp32/wifi`.

Fixes: d524015f82 ("samples: boards: remove esp32 wifi sample code")

Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>

drivers/wifi/esp32/Kconfig.esp32

@@ -19,16 +19,6 @@ menuconfig WIFI_ESP32
 
 if WIFI_ESP32
 
-config ESP32_WIFI_SSID
-	string "SSID of WiFi network"
-	help
-	  SSID (network name) for the application to connect to.
-
-config ESP32_WIFI_PASSWORD
-	string "Password (WPA or WPA2) of WiFi network"
-	help
-	  WiFi password (WPA or WPA2) for the example to use.
-
 config ESP32_WIFI_STA_AUTO_DHCPV4
 	bool "Automatically starts DHCP4 negotiation"
 	depends on NET_DHCPV4