arm: socfpga: Correct how we set BOOTFILE

In order to set the BOOTFILE symbol we first need to have USE_BOOTFILE
be set, or some of the logic might not work as expected later on when
building. Second, defaults like this belong with the symbol itself.

Fixes: da595d236b ("include: configs: soc64: Use CONFIG_SPL_ATF to differentiate bootfile")
Signed-off-by: Tom Rini <trini@konsulko.com>

arch/arm/Kconfig

@@ -22,9 +22,6 @@ config ARM64_CRC32
 	  not be present on all ARMv8.0, but is always present on ARMv8.1 and
 	  newer.
 
-config BOOTFILE
-	default kernel.itb if SPL_ATF && TARGET_SOCFPGA_SOC64
-
 config COUNTER_FREQUENCY
 	int "Timer clock frequency"
 	depends on ARM64 || CPU_V7A
@@ -1178,6 +1175,7 @@ config ARCH_SOCFPGA
 	select SYSRESET_SOCFPGA_SOC64 if !TARGET_SOCFPGA_AGILEX5 && \
            TARGET_SOCFPGA_SOC64
 	select SYSRESET_PSCI if TARGET_SOCFPGA_AGILEX5
+	select USE_BOOTFILE if SPL_ATF && TARGET_SOCFPGA_SOC64
 	imply CMD_DM
 	imply CMD_MTDPARTS
 	imply CRC32_VERIFY

env/Kconfig

@@ -957,6 +957,7 @@ config USE_BOOTFILE
 
 config BOOTFILE
 	string "'bootfile' environment variable value"
+	default kernel.itb if SPL_ATF && TARGET_SOCFPGA_SOC64
 	depends on USE_BOOTFILE
 	help
 	  The value to set the "bootfile" variable to.