Previously, this config was added to ensure that the size of the struct
file remained unchanged, thereby preventing the Flash memory of
resource-constrained MCUs from being unnecessarily increased.
However, we have now refactored the relationship between struct fd and struct file,
reducing their memory footprint in both Flash and RAM.
Consequently, this config can be removed.
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>