dmaengine: ALTERA_MSGDMA depends on HAS_IOMEM

dmaengine: ALTERA_MSGDMA depends on HAS_IOMEM

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: 3aecc600b902 ("dmaengine: Add driver for Altera / Intel mSGDMA IP core")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Reviewed-by: Stefan Roese <sr@denx.de>
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr@denx.de
Link: https://lore.kernel.org/r/20210522021313.16405-2-rdunlap@infradead.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>