zephyr: Remove CMakeLists.txt

The commit removes CmakeLists.txt and modifies zephyr/module.yml
to allow storing Zephyr specific sources in module/fatfs
directory of Zephyr project.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

CMakeLists.txt

@@ -1,18 +0,0 @@
-
-if(CONFIG_FAT_FILESYSTEM_ELM)
-add_library(ELMFAT INTERFACE)
-
-target_include_directories(ELMFAT INTERFACE include)
-
-zephyr_library()
-zephyr_library_sources(
-    ff.c
-    zfs_diskio.c
-    )
-zephyr_library_sources_ifdef(CONFIG_FS_FATFS_LFN
-    option/ffunicode.c
-    option/ffsystem.c
-)
-zephyr_library_link_libraries(ELMFAT)
-target_link_libraries(ELMFAT INTERFACE zephyr_interface)
-endif()

zephyr/module.yml

@@ -1,2 +1,3 @@
 build:
-  cmake: .
+  cmake-ext: True
+  kconfig-ext: True