net: phy: Factor manual relocation into separate function

net: phy: Factor manual relocation into separate function

Create separate function to implement manual relocation of PHY driver
functions and make use of that function. This is a preparatory patch
for introduction of PHY driver definition using linker lists.

No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Acked-by: Michal Simek <michal.simek@amd.com>
Tested-by: Michal Simek <michal.simek@amd.com> #microblaze (MANUAL_RELOC)