Generate dwarf4 debuginfo

configname: CONFIG_DEBUG_INFO_DWARF4

Linux Kernel Configuration
└─>Kernel hacking
└─>Compile-time checks and compiler options
└─>Generate dwarf4 debuginfo
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Generate dwarf4 debug info. This requires recent versions
of gcc and gdb. It makes the debug information larger.
But it significantly improves the success of resolving
variables in gdb on optimized code.