I think you don't have makedepend program installed.
To be sure change your Makefie - remove part of the command marked by red
makedepend -D_REENTRANT -DLINUX -Wall -O2 -mlong-calls -I/opt/mv_pro_4.0/montavista/pro/devkit/lsp/ti-davinci/include/ \
-I/home/huyh/DM6446-EVB/linux-2.6.10/include/ -f.depend ./video_test.c ./strfunc.c > /dev/null 2>&1
Also note that usually running build as root is a bad idea.
Create regular user and use it to this task