feat(libs): add libpng decoder (#4569)

Signed-off-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>

examples/libs/libpng/lv_example_libpng_1.py

@@ -0,0 +1,11 @@
+#!/opt/bin/lv_micropython -i
+import lvgl as lv
+import display_driver
+import fs_driver
+
+fs_drv = lv.fs_drv_t()
+fs_driver.fs_register(fs_drv, 'S')
+
+image = lv.image(lv.scr_act())
+image.set_src("S:png_demo.png")
+image.center()