in Android NDK, <elf.h> doesn't has define for:
NT_X86_XSTATE
NT_PRSTATUS

so add these defines to pass compile.

NOTE: add <linux/elf.h> will have more build errors

Cc: Chen Hu <hu1.chen@intel.com>
Signed-off-by: Zhang Ning <ning.a.zhang@intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>