s390/pci: enable NEED_DMA_MAP_STATE

The DMA API allows to avoid DMA unmaps because they are NOPs on some
plattforms. But not on s390, so force them.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -479,6 +479,9 @@ config NEED_SG_DMA_LENGTH
 config HAVE_DMA_ATTRS
 	def_bool PCI
 
+config NEED_DMA_MAP_STATE
+	def_bool PCI
+
 config CHSC_SCH
 	def_tristate m
 	prompt "Support for CHSC subchannels"