conf: machine: add AM68-SK machine configuration

As of commit [1] there will be a separate defconfig to build u-boot
for j721s2-evm and am68-sk.

Hence, introduce new yocto machine configs for am68-sk. This is done
through a new am68.inc file as the am68-sk platform does not support GP.
So j721s2-evm.inc is copied to am68.inc and updated accordingly.

[1]: https://source.denx.de/u-boot/u-boot/-/commit/a96be9b8c05ea835d27f7c9bae03279b8bd5dcf2

Signed-off-by: Aniket Limaye <a-limaye@ti.com>
Signed-off-by: Ryan Eatmon <reatmon@ti.com>

meta-ti-bsp/conf/machine/am68-sk-k3r5.conf

@@ -0,0 +1,11 @@
+#@TYPE: Machine
+#@NAME: AM68 SK (R5F)
+#@DESCRIPTION: Machine configuration for the TI AM68 SK (R5F core)
+
+require conf/machine/include/k3r5.inc
+
+SYSFW_SOC = "j721s2"
+SYSFW_CONFIG = "evm"
+SYSFW_SUFFIX = "hs-fs"
+
+UBOOT_MACHINE = "am68_sk_r5_defconfig"

meta-ti-bsp/conf/machine/am68-sk.conf

@@ -0,0 +1,20 @@
+#@TYPE: Machine
+#@NAME: AM68 SK
+#@DESCRIPTION: Machine configuration for the TI AM68 SK
+
+require conf/machine/include/am68.inc
+
+TFA_K3_USART = "0x8"
+OPTEE_K3_USART = "0x8"
+
+KERNEL_DEVICETREE_PREFIX = " \
+    ti/k3-am68-sk \
+    ti/k3-fpdlink \
+    ti/k3-v3link \
+"
+
+KERNEL_DEVICETREE = " \
+    ti/k3-am68-sk-base-board.dtb \
+"
+
+UBOOT_MACHINE = "am68_sk_a72_defconfig"

meta-ti-bsp/conf/machine/include/am68.inc

@@ -0,0 +1,19 @@
+require conf/machine/include/k3.inc
+SOC_FAMILY:append = ":j721s2"
+
+MACHINE_FEATURES += "screen gpu"
+
+require conf/machine/include/mesa-pvr.inc
+PREFERRED_PROVIDER_virtual/gpudriver ?= "ti-img-rogue-driver"
+
+# Default tiboot3.bin on AM68 is for SR1.0 HS-FS
+IMAGE_BOOT_FILES += "tiboot3-j721s2-hs-fs-evm.bin"
+
+# Since default tiboot3.bin on AM68 is for HS-FS, add a version for SR1.0 HS-SE
+IMAGE_BOOT_FILES += "tiboot3-j721s2-hs-evm.bin"
+
+TFA_BOARD = "generic"
+
+OPTEEMACHINE = "k3-j784s4"
+
+MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "cadence-mhdp-fw cnm-wave-fw"