net: lan743x: also select PHYLIB

Since FIXED_PHY depends on PHYLIB, PHYLIB needs to be set to avoid
a kconfig warning:

WARNING: unmet direct dependencies detected for FIXED_PHY
  Depends on [n]: NETDEVICES [=y] && PHYLIB [=n]
  Selected by [y]:
  - LAN743X [=y] && NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_MICROCHIP [=y] && PCI [=y] && PTP_1588_CLOCK_OPTIONAL [=y]

Fixes: 73c4d1b3

 ("net: lan743x: select FIXED_PHY")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: lore.kernel.org/r/202309261802.JPbRHwti-lkp@intel.com
Cc: Bryan Whitehead <bryan.whitehead@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested
Link: https://lore.kernel.org/r/20231002193544.14529-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>