[S390] Convert to SPARSEMEM & SPARSEMEM_VMEMMAP

Convert s390 to SPARSEMEM and SPARSEMEM_VMEMMAP. We do a select
of SPARSEMEM_VMEMMAP since it is configurable. This is because
SPARSEMEM without SPARSEMEM_VMEMMAP gives us a hell of broken
include dependencies that I don't want to fix.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/mm/init.c

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index acc92f4..fa31de6 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -106,6 +106,8 @@
 	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
 	__raw_local_irq_ssm(ssm_mask);
 
+	sparse_memory_present_with_active_regions(MAX_NUMNODES);
+	sparse_init();
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 #ifdef CONFIG_ZONE_DMA
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);