net: Remove unused CONFIG_DW_SEARCH_PHY from configs

Remove this symbol from configs, since it's unused.

Signed-off-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@ti.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Pavel Machek <pavel@denx.de>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Acked-by: Chin Liang See <clsee@altera.com>