phy: renesas: rcar-gen3-usb2: Simplify ID/VBUS detection logic

phy: renesas: rcar-gen3-usb2: Simplify ID/VBUS detection logic

Read USB2_ADPCTRL once in rcar_gen3_check_id() instead of issuing
multiple MMIO reads, and derive both IDDIG and VBUSVALID from the same
value.

Drop the redundant !! operator, as assigning a masked u32 value to a
bool already performs the required normalization. Simplify the logic by
comparing the ID and VBUS status directly, which is equivalent to the
previous conditional but easier to follow.

Reported-by: Pavel Machek <pavel@nabladev.com>
Closes: https://lore.kernel.org/all/acJVCOdlchLiSe5n@duo.ucw.cz/
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260325112039.464992-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>