To enable GDB server on any QorIQ platform you need the following components:
The gdbserver tools comes as part of the gdb package itself and the command to build it in Yocto SDK is "bitbake gdb".
And the command to build gdb for host system usage is "bitbake gdb-cross" and the binary is installed at "<Yocto SDK Home>/build_<platfrom_rdb>_release/tmp/sysroots/i686-linux/usr/bin/ppce5500-fsl-linux/powerpc-fsl-linux-gdb.
You can refer to the below link on the usage of GDB server
Cross debugging with GDB | STLinux
For GDB tool documentation please refer to the below link: