staging: fsl-mc: Move core bus out of staging

Move the source files out of staging into their final locations:
  -mc.h include file in drivers/staging/fsl-mc/include go to include/linux/fsl
  -source files in drivers/staging/fsl-mc/bus go to drivers/bus/fsl-mc
  -overview.rst, providing an overview of DPAA2, goes to
   Documentation/networking/dpaa2/overview.rst

Update or delete other remaining staging files -- Makefile, Kconfig, TODO.
Update dpaa2_eth and dpio staging drivers.
Add integration bits for the documentation build system.

Signed-off-by: Stuart Yoder <stuyoder@gmail.com>
[rebased, add dpaa2_eth and dpio #include updates]
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
[rebased, split irqchip to separate patch]
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@nxp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 9bcd0bf..b666c49 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -8,6 +8,10 @@
 obj-$(CONFIG_ARM_CCN)		+= arm-ccn.o
 
 obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
+
+# DPAA2 fsl-mc bus
+obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
+
 obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
 obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
 obj-$(CONFIG_MVEBU_MBUS) 	+= mvebu-mbus.o