fpga: region: move device tree support to of-fpga-region.c

Create of-fpga-region.c and move the following functions without
modification from fpga-region.c.

* of_fpga_region_find
* of_fpga_region_get_mgr
* of_fpga_region_get_bridges
* child_regions_with_firmware
* of_fpga_region_parse_ov
* of_fpga_region_notify_pre_apply
* of_fpga_region_notify_post_remove
* of_fpga_region_notify
* of_fpga_region_probe
* of_fpga_region_remove

Create two new functions with some code from fpga_region_init/exit.

* of_fpga_region_init
* of_fpga_region_exit
Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fpga/Kconfig

@@ -13,10 +13,18 @@ if FPGA
 
 config FPGA_REGION
 	tristate "FPGA Region"
-	depends on OF && FPGA_BRIDGE
+	depends on FPGA_BRIDGE
+	help
+	  FPGA Region common code.  A FPGA Region controls a FPGA Manager
+	  and the FPGA Bridges associated with either a reconfigurable
+	  region of an FPGA or a whole FPGA.
+
+config OF_FPGA_REGION
+	tristate "FPGA Region Device Tree Overlay Support"
+	depends on OF && FPGA_REGION
 	help
-	  FPGA Regions allow loading FPGA images under control of
-	  the Device Tree.
+	  Support for loading FPGA images by applying a Device Tree
+	  overlay.
 
 config FPGA_MGR_ICE40_SPI
 	tristate "Lattice iCE40 SPI"
@@ -74,7 +82,6 @@ config FPGA_MGR_ZYNQ_FPGA
 
 config FPGA_BRIDGE
 	tristate "FPGA Bridge Framework"
-	depends on OF
 	help
 	  Say Y here if you want to support bridges connected between host
 	  processors and FPGAs or between FPGAs.

drivers/fpga/Makefile

@@ -26,3 +26,4 @@ obj-$(CONFIG_XILINX_PR_DECOUPLER)	+= xilinx-pr-decoupler.o
 
 # High Level Interfaces
 obj-$(CONFIG_FPGA_REGION)		+= fpga-region.o
+obj-$(CONFIG_OF_FPGA_REGION)		+= of-fpga-region.o