Added GDB full debugger and GDB Server to the build

Packages added from make menuconfig:

BR2_PACKAGE_GDB:

Build the full gdb debugger to run on the target.

Symbol: BR2_PACKAGE_GDB [=y]
Type  : boolean
Prompt: Build gdb debugger for the Target
  Defined at toolchain/gdb/Config.in:3
  Depends on: BR2_USE_WCHAR [=y] && !BR2_sh [=n] && !BR2_sh64 [=n] && !BR2_avr32 [=n] && !BR2_microblaze [=n] && !\
BR2_bfin [=n] && !BR2_aarch64 [=n] && (BR2_TOOLCHAIN_HAS_THREADS_DEBUG_IF_NEEDED [=y] || BR2_DEPRECATED [=n] || \
BR2_bfin [=n])
  Location:
    -> Toolchain
  Selects: BR2_PACKAGE_NCURSES [=y]

BR2_PACKAGE_GDB_SERVER:

Build the gdbserver stub to run on the target.
A full gdb is needed to debug the progam.

Symbol: BR2_PACKAGE_GDB_SERVER [=y]
Type  : boolean
Prompt: Build gdb server for the Target
  Defined at toolchain/gdb/Config.in:21
  Depends on: !BR2_TOOLCHAIN_EXTERNAL [=n]
  Location:
    -> Toolchain