autofs: uprev it to 5.1.0

1. Uprev it to 5.1.0, add remove the unneed patches
2. fix a building failure since not include stdarg.h
3. using pkg-config to check xml and krb5
4. force STRIP to empty to not strip the file

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>