dt-bindings: pinctrl: k3: Introduce pinmux definitions for AM62A

Add pinctrl macros for AM62AX SoCs. These macro definitions are similar
to that of previous platforms, but adding new definitions to avoid any
naming confusions in the SoC dts files.

checkpatch insists the following error exists:
ERROR: Macros with complex values should be enclosed in parentheses

However, we do not need parentheses enclosing the values for this
macro as we do intend it to generate two separate values as has been
done for other similar platforms.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Tested-by: Devarsh Thakkar <devarsht@ti.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220901141328.899100-4-vigneshr@ti.com