[S390] Fix IPL from NSS.

IPL from NSS didn't work because the memory detection routine omits any
memory sections with a size lower than what MAX_ORDER defines.
This causes the detection routine to skip the first memory segment which
has a size of 1MB. Which later on will let the kernel think that there
is no memory available at all.
Since in addition the z/VM memory increment size is 1MB force MAX_ORDER
to be 9, so we can support 1MB segments.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -351,6 +351,10 @@ endchoice
 
 source "fs/Kconfig.binfmt"
 
+config FORCE_MAX_ZONEORDER
+	int
+	default "9"
+
 config PROCESS_DEBUG
 	bool "Show crashed user process info"
 	help