fpga: add altera freeze bridge support

Add a low level driver for Altera Freeze Bridges to the FPGA Bridge
framework.  A freeze bridge is a bridge that exists in the FPGA
fabric to isolate one region of the FPGA from the busses while that
one region is being reprogrammed.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Matthew Gerlach <mgerlach@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 5605ad6..8fe6a84 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -47,6 +47,15 @@
 	  Say Y to enable drivers for FPGA bridges for Altera SOCFPGA
 	  devices.
 
+config ALTERA_FREEZE_BRIDGE
+	tristate "Altera FPGA Freeze Bridge"
+	depends on ARCH_SOCFPGA && FPGA_BRIDGE
+	help
+	  Say Y to enable drivers for Altera FPGA Freeze bridges.  A
+	  freeze bridge is a bridge that exists in the FPGA fabric to
+	  isolate one region of the FPGA from the busses while that
+	  region is being reprogrammed.
+
 endif # FPGA
 
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