kexec-tools: Remove duplicate ultoa() definitions and redefine it

There exist duplicate ultoa() definitions in many archs, remove them,
and also redefine ultoa() in kexec/kexec.h to make it more readable.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Simon Horman <horms@kernel.org>
6 files changed