dt-bindings: mfd: syscon: Add ti,am62-usb-phy-ctrl compatible

dt-bindings: mfd: syscon: Add ti,am62-usb-phy-ctrl compatible

Add the compatible for TI AM62 USB PHY Control register. This
register is found in the TI AM62 WKUP_CTRL_MMR0 space [1]. It
is used to indicate the USB PHY PLL reference clock rate and
core voltage level to the USB controller.

[1] - https://www.ti.com/lit/pdf/spruiv7

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240226-b4-for-v6-5-am62-usb-typec-dt-v6-1-acf77fff4344@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>