mips: mscc: luton+ocelot: Remove board config options, do probing

As we are moving to multi-dtb and board detection, remove static board
config options, and introduce board probing instead.

Luton: This add single-binary support for the two MSCC luton-based
reference boards - pcb090 and pcb091. The SoC chip ID is used to
determine the board type.

Ocelot: This add single-binary support for the two MSCC ocelot-based
reference boards - pcb120 and pcb123. The PHY ids on specific ports
are used to determine the board type.

Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
diff --git a/arch/mips/mach-mscc/Kconfig b/arch/mips/mach-mscc/Kconfig
index 0e35b77..37ef432 100644
--- a/arch/mips/mach-mscc/Kconfig
+++ b/arch/mips/mach-mscc/Kconfig
@@ -15,48 +15,30 @@
 config SYS_SOC
 	default "mscc"
 
+choice
+
+	prompt "SOC Family Variant"
+
 config SOC_OCELOT
-	bool
+	bool "Ocelot SOC Family"
 	select SOC_VCOREIII
+	select DESIGNWARE_SPI
 	help
 	  This supports MSCC Ocelot family of SOCs.
 
 config SOC_LUTON
-	bool
+	bool "Luton SOC Family"
 	select SOC_VCOREIII
+	select MSCC_BITBANG_SPI_GPIO
 	help
 	  This supports MSCC Luton family of SOCs.
 
+endchoice
+
 config SYS_CONFIG_NAME
 	default "vcoreiii"
 
 choice
-	prompt "Board select"
-
-config TARGET_OCELOT_PCB120
-	bool "MSCC PCB120 Reference Board (aka VSC5635EV)"
-	select SOC_OCELOT
-	help
-	  When selected, CONFIG_DEFAULT_DEVICE_TREE should be set to
-	  ocelot_pcb120
-
-config TARGET_OCELOT_PCB123
-	bool "MSCC PCB123 Reference Board (aka VSC7514EV))"
-	select SOC_OCELOT
-	help
-	  When selected, CONFIG_DEFAULT_DEVICE_TREE should be set to
-	  ocelot_pcb123
-
-config TARGET_LUTON_PCB091
-	bool "MSCC PCB091 Reference Board"
-	select SOC_LUTON
-	select MSCC_BITBANG_SPI_GPIO
-	help
-	  When selected, CONFIG_DEFAULT_DEVICE_TREE should be set to
-	  luton_pcb091
-endchoice
-
-choice
 	prompt "DDR type"
 
 config DDRTYPE_H5TQ4G63MFR