dma: add driver for R-Car HPB-DMAC

Add support for HPB-DMAC found in Renesas R-Car SoCs, using 'shdma-base' DMA
driver framework.

Based on the original patch by Phil Edworthy <phil.edworthy@renesas.com>.

Signed-off-by: Max Filippov <max.filippov@cogentembedded.com>
[Sergei: removed useless #include, sorted #include's, fixed HPB_DMA_TCR_MAX,
fixed formats and removed line breaks in the dev_dbg() calls, rephrased and
added IRQ # to the shdma_request_irq() failure message, added MODULE_AUTHOR(),
removed '__init'/'__exit' annotations from the probe()/remove() methods, removed
'__initdata' annotation from 'hpb_dmae_driver', fixed guard macro name in the
header file, fixed #define ASYNCRSTR_ASRST20, added #define ASYNCRSTR_ASRST24,
added the necessary runtime PM calls to the probe() and remove() methods,
handled errors returned by dma_async_device_register(), beautified comments
and #define's.]
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sh/Kconfig

@@ -22,3 +22,9 @@ config SUDMAC
 	depends on SH_DMAE_BASE
 	help
 	  Enable support for the Renesas SUDMAC controllers.
+
+config RCAR_HPB_DMAE
+	tristate "Renesas R-Car HPB DMAC support"
+	depends on SH_DMAE_BASE
+	help
+	  Enable support for the Renesas R-Car series DMA controllers.

drivers/dma/sh/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o shdma-of.o
 obj-$(CONFIG_SH_DMAE) += shdma.o
 obj-$(CONFIG_SUDMAC) += sudmac.o
+obj-$(CONFIG_RCAR_HPB_DMAE) += rcar-hpbdma.o