arm: socfpga: Move Stratix10 and Agilex to use TARGET_SOCFPGA_SOC64

Create common macro TARGET_SOCFPGA_SOC64 for Stratix10 and Agilex.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 4d4ff16..9b1abda 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -38,6 +38,7 @@
 	select FPGA_INTEL_SDM_MAILBOX
 	select NCORE_CACHE
 	select SPL_CLK if SPL
+	select TARGET_SOCFPGA_SOC64
 
 config TARGET_SOCFPGA_ARRIA5
 	bool
@@ -75,12 +76,16 @@
 	imply SPL_SYS_MALLOC_SIMPLE
 	imply SPL_USE_TINY_PRINTF
 
+config TARGET_SOCFPGA_SOC64
+	bool
+
 config TARGET_SOCFPGA_STRATIX10
 	bool
 	select ARMV8_MULTIENTRY
 	select ARMV8_SET_SMPEN
 	select BINMAN if SPL_ATF
 	select FPGA_INTEL_SDM_MAILBOX
+	select TARGET_SOCFPGA_SOC64
 
 choice
 	prompt "Altera SOCFPGA board select"