ARM: add __aeabi_unwind_cpp_pr0() function to avoid linker complaints

用arm-none-linux-gnueabi-gcc 编译uboot是
抱怨 add __aeabi_unwind_cpp_pr0() 解决补丁，
以前一直认为是编译器不匹配

针对u-boot-2009.08
diff --git a/lib_arm/eabi_compat.c b/lib_arm/eabi_compat.c
index 86eacf1..eb3e26d 100755
--- a/lib_arm/eabi_compat.c
+++ b/lib_arm/eabi_compat.c
@@ -16,3 +16,8 @@ int raise (int signum)
     printf("raise: Signal # %d caught\n", signum);
     return 0;
 }
+
+/* Dummy function to avoid linker complaints */
+void __aeabi_unwind_cpp_pr0(void)
+{
+};