openssh: bump to version 7.9p1

Drop patch #1. uClibc no longer includes pthreads.h indirectly.

Drop patch #2. The sys/param.h header is included indirectly through the
local includes.h header since version 6.8p1.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>