linux-imx

xtensa: drop unused declarations from elf.h

do_copy_regs, do_restore_regs, do_save_fpregs and do_restore_fpregs are
not used or implemented by xtensa, drop these declarations from the
arch/xtensa/include/asm/elf.h

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>