🧹 (icu_lib/endecoder/lvgl): add unused attribute to reserved field

Added the `#[allow(unused)]` attribute to the `reserved` field in `ImageCompressedHeader` to suppress warnings about its usage.

Signed-off-by: Benign X <[email protected]>

icu_lib/src/endecoder/lvgl/mod.rs

@@ -90,6 +90,8 @@ pub enum Compress {
 #[repr(C, packed)]
 struct ImageCompressedHeader {
     method: Compress,       /*Compression method, see `lv_image_compress_t`*/
+
+    #[allow(unused)]
     reserved: B28,          /*Reserved to be used later*/
     compressed_size: u32,   /*Compressed data size in byte*/
     decompressed_size: u32, /*Decompressed data size in byte*/