fix(esp_libc/cmake): add vfs as requirement if CONFIG_VFS_SUPPORT_IO is enabled

The esp_libc relies on the stdio implementation of the vfs component if
CONFIG_VFS_SUPPORT_IO is enabled. This is not an issue in cmakev1
because if the vfs component is not included in the project build, its
configuration is not available, and CONFIG_VFS_SUPPORT_IO is not set.
However, in cmakev2, the configuration for all components is available,
and the presence of some component configuration options does not
necessarily mean that the component is included in the project build.
When esp_libc is compiled without the vfs dependency but with
CONFIG_VFS_SUPPORT_IO enabled, the libc initialization will encounter a
panic due to a NULL pointer dereference (fp->_flags) in __swsetup_r, as
fopen in esp_libc_init_global_stdio will return NULL.

components/esp_libc/CMakeLists.txt

@@ -77,10 +77,18 @@ else()
     list(APPEND ldfragments src/picolibc/libc.lf)
 endif()
 
+set(priv_reqs soc spi_flash)
+
+if(IDF_BUILD_V2)
+    if(CONFIG_VFS_SUPPORT_IO)
+        list(APPEND priv_reqs vfs)
+    endif()
+endif()
+
 idf_component_register(SRCS "${srcs}"
                     INCLUDE_DIRS platform_include
                     PRIV_INCLUDE_DIRS priv_include
-                    PRIV_REQUIRES soc spi_flash
+                    PRIV_REQUIRES "${priv_reqs}"
                     LDFRAGMENTS "${ldfragments}")
 
 # Toolchain libraries require code defined in this component