bootloaders: add bootloaders-next manifest

For the SDK 10.0 release, we have been requested to maintain 2 versions of
bootloaders:

1. U-Boot 2023.04: the stable release, can be fetched with bootloaders.xml
2. U-Boot 2024.04: the next release, can be fetched with bootloaders-next.xml

Add a new manifest for U-Boot 2024.04 so that users can try it out and
experiment with the new bootmeth_android bootflow.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

bootloaders-next.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<manifest>
+    <remote name="baylibre" fetch="ssh://git@gitlab.baylibre.com/baylibre/ti" />
+    <remote name="ti" fetch="git://git.ti.com/" />
+    <remote name="github" fetch="https://github.com/" />
+
+    <project name="android/bootloader/build-bootloaders.git" path="build" remote="baylibre" revision="integ/ti-u-boot-2024.04" />
+    <project name="ti-u-boot" path="u-boot" remote="baylibre" revision="integ/ti-u-boot-2024.04" />
+    <project name="atf/arm-trusted-firmware.git" path="arm-trusted-firmware" remote="ti" revision="refs/tags/09.02.00.009" clone-depth="1" />
+    <project name="optee/ti-optee-os" path="optee-os" remote="ti" revision="refs/tags/09.02.00.009" />
+    <project name="OP-TEE/optee_test.git" path="optee-ta/optee_test" remote="github" revision="refs/tags/4.1.0" />
+    <project name="android/aosp/external/kmgk.git" path="optee-ta/kmgk" remote="baylibre" revision="ti-android-14"/>
+    <project name="processor-firmware/ti-linux-firmware.git" path="ti-linux-firmware" remote="ti" revision="refs/tags/09.02.00.009" clone-depth="1"/>
+</manifest>