When CONFIG_HAS_IOMEM is not set/enabled, certain iomap() family
functions [including ioremap(), devm_ioremap(), etc.] are not
available.
Drivers that use these functions should depend on HAS_IOMEM so that
they do not cause build errors.

Repairs this build error:
s390-linux-ld: drivers/dma/altera-msgdma.o: in function `request_and_map':
altera-msgdma.c:(.text+0x14b0): undefined reference to `devm_ioremap'

Fixes: a85c6f1b2921 ("dmaengine: Add driver for Altera / Intel mSGDMA IP core")
Signed-off-by: Randy Dunlap <redacted>
Reported-by: kernel test robot <redacted>
Cc: Stefan Roese <sr@denx.de>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
---
 drivers/dma/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- linux-next-20210521.orig/drivers/dma/Kconfig
+++ linux-next-20210521/drivers/dma/Kconfig

@@ -59,6 +59,7 @@ config DMA_OF
 #devices
 config ALTERA_MSGDMA
 	tristate "Altera / Intel mSGDMA Engine"
+	depends on HAS_IOMEM
 	select DMA_ENGINE
 	help
 	  Enable support for Altera / Intel mSGDMA controller.