usb: renesas_usbhs: Correct function references in comment

Update the comment to reference `usbhs_mod_probe()` instead of
`usbhs_mod_init()`, and replace `dev_set_drvdata()` with
`platform_set_drvdata()`, as these are the correct functions used
in this context.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20250407105002.107181-2-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>