net: phy: Remove unused NEEDS_MANUAL_RELOC code bits

The last user of the NEEDS_MANUAL_RELOC has been removed in commit
26af162a ("arch: m68k: Implement relocation")
Remove now unused NEEDS_MANUAL_RELOC code.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>