treewide: Move CONFIG_PHY_MARVELL to Kconfig

The CONFIG_PHY_MARVELL has already been migrated to Kconfig (some boards
already had it in their Kconfig), but had not been moved for older
boards.

Move it to the defconfigs for all boards.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig b/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
index ecdc472..1225b40 100644
--- a/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
+++ b/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
@@ -27,6 +27,7 @@
 # CONFIG_MMC is not set
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_PHY_MARVELL=y
 CONFIG_NETDEVICES=y
 CONFIG_TSEC_ENET=y
 # CONFIG_PCI is not set