arm64: visconti: Add initial support for Toshiba Visconti platform

Add the initial device tree files for Toshiba Visconti platform.
For starters, the only SoC supported will be Visconti5 TMPV7708.

https://toshiba.semicon-storage.com/ap-en/semiconductor/product/image-recognition-processors-visconti.html

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>

arch/arm64/Kconfig.platforms

@@ -300,6 +300,13 @@ config ARCH_VEXPRESS
 	  This enables support for the ARMv8 software model (Versatile
 	  Express).
 
+config ARCH_VISCONTI
+	bool "Toshiba Visconti SoC Family"
+	select PINCTRL
+	select PINCTRL_VISCONTI
+	help
+	  This enables support for Toshiba Visconti SoCs Family.
+
 config ARCH_VULCAN
 	def_bool n