If phy is PHY_NONE, the shift to register bits becomes negative. Check
and warn about this.
Reported-by: Ncoverity-bot <keescook@chromium.org>
References: https://lore.kernel.org/r/202211180848.D39006C@keescookSigned-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122120948.3436180-1-jani.nikula@intel.com