arm: dts: dt-bindings: Add Renesas RZ/A1 pinctrl header

Add dt-bindings for Renesas r7s72100 pin controller header file.
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

include/dt-bindings/pinctrl/r7s72100-pinctrl.h

+/*
+ * Defines macros and constants for Renesas RZ/A1 pin controller pin
+ * muxing functions.
+ */
+#ifndef __DT_BINDINGS_PINCTRL_RENESAS_RZA1_H
+#define __DT_BINDINGS_PINCTRL_RENESAS_RZA1_H
+
+#define RZA1_PINS_PER_PORT	16
+
+/*
+ * Create the pin index from its bank and position numbers and store in
+ * the upper 16 bits the alternate function identifier
+ */
+#define RZA1_PINMUX(b, p, f)	((b) * RZA1_PINS_PER_PORT + (p) | (f << 16))
+
+#endif /* __DT_BINDINGS_PINCTRL_RENESAS_RZA1_H */