arm: mach-k3: j721e: Move board selection to mach-k3

Currently each set of board targets from a vendor is selected inside
the board directory for that vendor. This has the problem of multiple
targets, one from each vendor, being selectable at the same time.
For instance you can select both TARGET_AM654_A53_EVM and
TARGET_IOT2050_A53 in the same build.

To fix this we need to move the target board choice to a common location
for each parent SoC selection. Do this in arch/arm/mach-k3.

Signed-off-by: Andrew Davis <afd@ti.com>
diff --git a/arch/arm/mach-k3/Kconfig b/arch/arm/mach-k3/Kconfig
index 9168bf8..d5fdabe 100644
--- a/arch/arm/mach-k3/Kconfig
+++ b/arch/arm/mach-k3/Kconfig
@@ -191,7 +191,7 @@
 source "board/ti/am64x/Kconfig"
 source "board/ti/am62x/Kconfig"
 source "board/ti/am62ax/Kconfig"
-source "board/ti/j721e/Kconfig"
+source "arch/arm/mach-k3/j721e/Kconfig"
 source "board/siemens/iot2050/Kconfig"
 source "board/ti/j721s2/Kconfig"
 source "board/toradex/verdin-am62/Kconfig"
diff --git a/arch/arm/mach-k3/j721e/Kconfig b/arch/arm/mach-k3/j721e/Kconfig
new file mode 100644
index 0000000..07cdb5c
--- /dev/null
+++ b/arch/arm/mach-k3/j721e/Kconfig
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+#	Andrew Davis <afd@ti.com>
+
+if SOC_K3_J721E
+
+choice
+	prompt "K3 J721E based boards"
+	optional
+
+config TARGET_J721E_A72_EVM
+	bool "TI K3 based J721E EVM running on A72"
+	select ARM64
+	select BOARD_LATE_INIT
+	imply TI_I2C_BOARD_DETECT
+	select SYS_DISABLE_DCACHE_OPS
+	select BINMAN
+
+config TARGET_J721E_R5_EVM
+	bool "TI K3 based J721E EVM running on R5"
+	select CPU_V7R
+	select SYS_THUMB_BUILD
+	select K3_LOAD_SYSFW
+	select RAM
+	select SPL_RAM
+	select K3_DDRSS
+	select BINMAN
+	imply SYS_K3_SPL_ATF
+	imply TI_I2C_BOARD_DETECT
+
+config TARGET_J7200_A72_EVM
+	bool "TI K3 based J7200 EVM running on A72"
+	select ARM64
+	select BOARD_LATE_INIT
+	imply TI_I2C_BOARD_DETECT
+	select SYS_DISABLE_DCACHE_OPS
+	select BINMAN
+
+config TARGET_J7200_R5_EVM
+	bool "TI K3 based J7200 EVM running on R5"
+	select CPU_V7R
+	select SYS_THUMB_BUILD
+	select K3_LOAD_SYSFW
+	select RAM
+	select SPL_RAM
+	select K3_DDRSS
+	select BINMAN
+	imply SYS_K3_SPL_ATF
+	imply TI_I2C_BOARD_DETECT
+
+endchoice
+
+source "board/ti/j721e/Kconfig"
+
+endif