linux: use stable ref for baseline and dev for dev group

Right now we have the default tree being selected for the "baseline"
group. However when booting with BOOTLINUX_AB_DIFFERENT_REF we end up
with a baseline group and "dev" group.

Is is therefore odd, to end up up with the "stable" kernel on the "dev"
group, and the latest kernel on the "baseline" group. Invert this logic,
so the dev group always has the latest and greatest to match expectations
that dev groups are the bleeding edge.

Now we get more sensible defaults:

$ make defconfig-mmtests-ab-testing-thpcompact KDEVOPS_HOSTS_PREFIX="lpc"
$ make
$ make bringup
$ make bringup
$ make uname

lpc-thpcompact-dev               6.17.0-rc4-00047-ge6b9dce0aeeb
lpc-thpcompact                   6.15.0

Signed-off-by: Luis Chamberlain <[email protected]>

Author: mcgrof

workflows/linux/Kconfig

@@ -307,7 +307,7 @@ config BOOTLINUX_TEST_MESSAGE_ID_INSTALL_B4
 	help
 	  When enabled, b4 will be installed using pip
 
-config BOOTLINUX_TREE_REF
+config LATEST_BOOTLINUX_TREE_REF
 	string
 	default BOOTLINUX_TREE_LINUS_REF if BOOTLINUX_TREE_LINUS
 	default BOOTLINUX_TREE_STABLE_REF if BOOTLINUX_STABLE
@@ -324,6 +324,11 @@ config BOOTLINUX_TREE_REF
 	default BOOTLINUX_TREE_CEL_LINUX_REF if BOOTLINUX_TREE_CEL_LINUX
 	default BOOTLINUX_TREE_CUSTOM_REF if BOOTLINUX_CUSTOM
 
+config BOOTLINUX_TREE_REF
+	string
+	default LATEST_BOOTLINUX_TREE_REF if !BOOTLINUX_AB_DIFFERENT_REF
+	default $(shell, scripts/infer_last_stable_kernel.sh) if BOOTLINUX_AB_DIFFERENT_REF
+
 config BOOTLINUX_TREE_CUSTOM_KERNELRELEASE
 	bool "Do you want a full custom kernel release name?"
 	output yaml
@@ -424,7 +429,7 @@ config BOOTLINUX_DEV_TREE
 config TARGET_LINUX_DEV_REF
 	string "Development kernel reference"
 	output yaml
-	default $(shell, scripts/infer_last_stable_kernel.sh)
+	default LATEST_BOOTLINUX_TREE_REF
 	help
 	  Git reference (branch, tag, or commit) for the development kernel.
 	  This should be different from the baseline reference to enable