package/kexec-lite: update to latest version

Upstream now supports little endian, so enable for little-endian
powerpc.

[Peter: add hash]
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>