Add new NT_PPC_* available since Linux 4.8

Add new note types available since Linux 4.8 to elf/common.h and
make the 'readelf' tool aware of it.

include/
	* elf/common.h (NT_PPC_TAR): New macro.
	(NT_PPC_PPR): Likewise.
	(NT_PPC_DSCR): Likewise.
	(NT_PPC_EBB): Likewise.
	(NT_PPC_PMU): Likewise.
	(NT_PPC_TM_CGPR): Likewise.
	(NT_PPC_TM_CFPR): Likewise.
	(NT_PPC_TM_CVMX): Likewise.
	(NT_PPC_TM_CVSX): Likewise.
	(NT_PPC_TM_SPR): Likewise.
	(NT_PPC_TM_CTAR): Likewise.
	(NT_PPC_TM_CPPR): Likewise.
	(NT_PPC_TM_CDSCR): Likewise.
binutils/
	* readelf.c (get_note_type): Handle PPC note types available
	since Linux 4.8.