pinctrl: meson: rework gx pmx function

In preparation of supporting the new Amlogix AGX SoCs, we need to move
the Amlogic GX pinmux functions out of the common code to be able to
add a different set of SoC specific pinmux functions for AXG.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/pinctrl/meson/Kconfig b/drivers/pinctrl/meson/Kconfig
index 27ba890..15a8d9c 100644
--- a/drivers/pinctrl/meson/Kconfig
+++ b/drivers/pinctrl/meson/Kconfig
@@ -4,12 +4,16 @@
 	depends on PINCTRL_GENERIC
 	bool
 
+config PINCTRL_MESON_GX_PMX
+	select PINCTRL_MESON
+	bool
+
 config PINCTRL_MESON_GXBB
 	bool "Amlogic Meson GXBB SoC pinctrl driver"
-	select PINCTRL_MESON
+	select PINCTRL_MESON_GX_PMX
 
 config PINCTRL_MESON_GXL
 	bool "Amlogic Meson GXL SoC pinctrl driver"
-	select PINCTRL_MESON
+	select PINCTRL_MESON_GX_PMX
 
 endif