Hi Sujan,
It's a good that you can build the u-boot, but I think that it's not good idea to make changes in a Makefile. I'll try to explain the following line from the previous post:
2. export ARCH=arm
3. export CROSS_COMPILE=~/ti-sdk-am335x-evm-06.00.00.00/linux-devkit/sysroots/i686-arago-linux/usr/bin/arm-linux-gnueabihf-
4. make am335x_evm
With 2. we tell on the toolchain the architecture of the processor.
With 3. we tell which compiler we use and where is his places.
With 4. we compile just our board. The name is am335x_evm. In the directory include/configs/ you can see that packets support too many board, and this way we choose exactly our board.
Other way to explain this is:
export CROSS_COMPILE=arm-linux-gnueabihf-
export ARCH=arm
export PATH=$PATH:$HOME/ti-sdk-am335x-evm-06.00.00.00/linux-devkit/sysroots/i686-arago-linux/usr/bin
BR
Ivan