Revert "drivers: net: driver for MDIO muxes controlled over I2C"

This reverts commit d9a9174fa5687521035b2ec82cce86cdcf4f36e6.
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 084e095..6eb22df 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -595,12 +595,4 @@
 	  This driver supports the NXP ENETC Ethernet controller found on some
 	  of the NXP SoCs.
 
-config MDIO_MUX_I2CREG
-	bool "MDIO MUX accessed as a register over I2C"
-	depends on DM_MDIO_MUX && DM_I2C
-	help
-	  This driver is used for MDIO muxes driven by writing to a register of
-	  an I2C chip.  The board it was developed for uses a mux controlled by
-	  on-board FPGA which in turn is accessed as a chip over I2C.
-
 endif # NETDEVICES
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 71c0889..b6e40df 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -37,7 +37,6 @@
 obj-$(CONFIG_LPC32XX_ETH) += lpc32xx_eth.o
 obj-$(CONFIG_MACB) += macb.o
 obj-$(CONFIG_MCFFEC) += mcffec.o mcfmii.o
-obj-$(CONFIG_MDIO_MUX_I2CREG) += mdio_mux_i2creg.o
 obj-$(CONFIG_MDIO_MUX_SANDBOX) += mdio_mux_sandbox.o
 obj-$(CONFIG_MPC8XX_FEC) += mpc8xx_fec.o
 obj-$(CONFIG_MT7628_ETH) += mt7628-eth.o