s390/mmap: increase stack/mmap gap to 128MB

This basically reverts commit 9e78a13b ("[S390] reduce miminum
gap between stack and mmap_base"). 32MB is not enough space
between stack and mmap for some programs. Given that compat
task aren't common these days, lets revert back to 128MB.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/mm/mmap.c

@@ -58,9 +58,9 @@ static inline unsigned long mmap_base(unsigned long rnd,
 
 	/*
 	 * Top of mmap area (just below the process stack).
-	 * Leave at least a ~32 MB hole.
+	 * Leave at least a ~128 MB hole.
 	 */
-	gap_min = 32 * 1024 * 1024UL;
+	gap_min = SZ_128M;
 	gap_max = (STACK_TOP / 6) * 5;
 
 	if (gap < gap_min)