arm: socfpga: arria10: add option to reprogram the FPGA every reboot

Add Kconfig that enables FPGA reprogramming with warm boot on Arria 10.
This option allows to change the bitstream on the filesystem and apply
changes with warm reboot without the need for a power cycle.

Signed-off-by: Michał Barnaś <barnas@google.com>
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 1008232..6b6a162 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -90,6 +90,14 @@
 	imply FPGA_SOCFPGA
 	imply SPL_USE_TINY_PRINTF
 
+config SOCFPGA_ARRIA10_ALWAYS_REPROGRAM
+	bool "Always reprogram Arria 10 FPGA"
+	depends on TARGET_SOCFPGA_ARRIA10
+	help
+	  Arria 10 FPGA is only programmed during the cold boot.
+	  This option forces the FPGA to be reprogrammed every reboot,
+	  allowing to change the bitstream and apply it with warm reboot.
+
 config TARGET_SOCFPGA_CYCLONE5
 	bool
 	select TARGET_SOCFPGA_GEN5