This helps to avoid several merge conflicts later.

* fixes:
  s390/extable: fix exception table sorting
  s390/ftrace: fix arch_ftrace_get_regs implementation
  s390/ftrace: fix ftrace_caller/ftrace_regs_caller generation
  s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE
  s390/cio: verify the driver availability for path_event call
  s390/module: fix building test_modules_helpers.o with clang
  MAINTAINERS: downgrade myself to Reviewer for s390
  MAINTAINERS: add Alexander Gordeev as maintainer for s390
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>