lvgl: use the C library allocator

The builtin pool of LVGL has a fixed size (64 KB by default). When it
runs out, LV_ASSERT_HANDLER (while(1)) is called and the recovery GUI
hangs at 100% CPU, for example when the network setup screen is opened.
Use the allocator of the C library instead.

Signed-off-by: Stefano Babic <stefano.babic@swupdate.org>

recipes-graphics/lvgl/files/clib-malloc.cfg

@@ -0,0 +1,4 @@
+# Use the C library allocator instead of LVGL's builtin pool. The builtin
+# pool has a fixed size (64 KB by default) and running out of it ends in
+# LV_ASSERT_HANDLER (while(1)): the recovery GUI hangs at 100% CPU.
+CONFIG_LV_USE_CLIB_MALLOC=y

recipes-graphics/lvgl/lvgl_%.bbappend

@@ -1 +1,5 @@
+FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
+
 PACKAGECONFIG += "fbdev gridnav"
+
+SRC_URI += "file://clib-malloc.cfg"