Support for LibreTiny platform (RTL8710, BK7231 & other modules) (#3509)

Co-authored-by: Kuba Szczodrzyński <kuba@szczodrzynski.pl>
Co-authored-by: Sam Neirinck <git@samneirinck.com>
Co-authored-by: David Buezas <dbuezas@users.noreply.github.com>
Co-authored-by: Stroe Andrei Catalin <catalin2402@gmail.com>
Co-authored-by: Sam Neirinck <github@samneirinck.be>
Co-authored-by: Péter Sárközi <xmisterhu@gmail.com>
Co-authored-by: Hajo Noerenberg <hn@users.noreply.github.com>

esphome/components/rp2040/gpio.py

@@ -1,6 +1,7 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome.const import (
+    CONF_ANALOG,
     CONF_ID,
     CONF_INPUT,
     CONF_INVERTED,
@@ -76,8 +77,6 @@ def validate_supports(value):
     return value
 
 
-CONF_ANALOG = "analog"
-
 RP2040_PIN_SCHEMA = cv.All(
     cv.Schema(
         {