lib: tenstorrent: banner: use APPLICATION_SOURCE_DIR for git describe

Use APPLICATION_SOURCE_DIR for the `git describe` step- otherwise, git
describe will fail when building the application from outside of the
tt-zephyr-platforms repo

Signed-off-by: Daniel DeGrasse <[email protected]>

Author: danieldegrasse

lib/tenstorrent/banner/CMakeLists.txt

@@ -6,7 +6,7 @@ zephyr_library_sources(tt_banner.c)
 if(CONFIG_TT_BOOT_BANNER_GIT_VERSION)
 
 include(${ZEPHYR_BASE}/cmake/modules/git.cmake)
-git_describe(. TT_GIT_VERSION)
+git_describe(${APPLICATION_SOURCE_DIR} TT_GIT_VERSION)
 zephyr_library_compile_definitions(TT_GIT_VERSION="${TT_GIT_VERSION}")
 
 endif()