net: phy: mdio-sun4i: don't select REGULATOR

The mdio-sun4i driver automatically selects REGULATOR and
REGULATOR_FIXED_VOLTAGE because it uses the regulator API. But a
driver selecting a subsystem increases the chance of generating
circular Kconfig dependencies, especially when other drivers depend on
the selected symbol.

Since the regulator API functions are replaced with no-ops when
REGULATOR is disabled, the driver can be built successfully even
without regulator support and so those 'select' dependencies can be
safely dropped.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/Kconfig

@@ -159,8 +159,6 @@ config MDIO_OCTEON
 config MDIO_SUN4I
 	tristate "Allwinner sun4i MDIO interface support"
 	depends on ARCH_SUNXI
-	select REGULATOR
-	select REGULATOR_FIXED_VOLTAGE
 	help
 	  This driver supports the MDIO interface found in the network
 	  interface units of the Allwinner SoC that have an EMAC (A10,