arm: socfpga: Unbind CPU type from board type

The CONFIG_TARGET_SOCFPGA_CYCLONE5 and CONFIG_TARGET_SOCFPGA_ARRIA5
selected both a board and a CPU. This is not correct as these macros
are supposed to select only board.

All would be good, if QTS-generated header files didn't check for
these macros exactly to determine if the platform is Cyclone V or
Arria V. Thus, for the sake of compatibility with not well fleshed
out header file generator, this patch makes these two macros into
a stub config option and introduces new CONFIG_TARGET_SOCFPGA_CYCLONE5_SOCDK
and CONFIG_TARGET_SOCFPGA_ARRIA5_SOCDK targets, which select the
previous stub config option.

The result is that compatibility with QTS is preserved and the new
CONFIG_TARGET_* select actual target boards.

Signed-off-by: Marek Vasut <marex@denx.de>

arch/arm/mach-socfpga/Kconfig

 if ARCH_SOCFPGA
 
+config TARGET_SOCFPGA_ARRIA5
+	bool
+
+config TARGET_SOCFPGA_CYCLONE5
+	bool
+
 choice
 	prompt "Altera SOCFPGA board select"
 	optional
 
-config TARGET_SOCFPGA_ARRIA5
-	bool "Altera SOCFPGA Arria V"
+config TARGET_SOCFPGA_ARRIA5_SOCDK
+	bool "Altera SOCFPGA SoCDK (Arria V)"
+	select TARGET_SOCFPGA_ARRIA5
 
-config TARGET_SOCFPGA_CYCLONE5
-	bool "Altera SOCFPGA Cyclone V"
+config TARGET_SOCFPGA_CYCLONE5_SOCDK
+	bool "Altera SOCFPGA SoCDK (Cyclone V)"
+	select TARGET_SOCFPGA_CYCLONE5
 
 endchoice
 
 config SYS_BOARD
-	default "socfpga"
+	default "socfpga" if TARGET_SOCFPGA_ARRIA5_SOCDK
+	default "socfpga" if TARGET_SOCFPGA_CYCLONE5_SOCDK
 
 config SYS_VENDOR
-	default "altera"
+	default "altera" if TARGET_SOCFPGA_ARRIA5_SOCDK
+	default "altera" if TARGET_SOCFPGA_CYCLONE5_SOCDK
 
 config SYS_SOC
 	default "socfpga"
 
 config SYS_CONFIG_NAME
-	default "socfpga_arria5" if TARGET_SOCFPGA_ARRIA5
-	default "socfpga_cyclone5" if TARGET_SOCFPGA_CYCLONE5
+	default "socfpga_arria5" if TARGET_SOCFPGA_ARRIA5_SOCDK
+	default "socfpga_cyclone5" if TARGET_SOCFPGA_CYCLONE5_SOCDK
 
 endif

configs/socfpga_arria5_defconfig

 CONFIG_ARM=y
 CONFIG_ARCH_SOCFPGA=y
 CONFIG_TARGET_SOCFPGA_ARRIA5=y
+CONFIG_TARGET_SOCFPGA_ARRIA5_SOCDK=y
 CONFIG_DEFAULT_DEVICE_TREE="socfpga_arria5_socdk"
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set

configs/socfpga_cyclone5_defconfig

 CONFIG_ARM=y
 CONFIG_ARCH_SOCFPGA=y
 CONFIG_TARGET_SOCFPGA_CYCLONE5=y
+CONFIG_TARGET_SOCFPGA_CYCLONE5_SOCDK=y
 CONFIG_DEFAULT_DEVICE_TREE="socfpga_cyclone5_socdk"
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set

configs/socfpga_socrates_defconfig

 CONFIG_ARM=y
 CONFIG_ARCH_SOCFPGA=y
 CONFIG_TARGET_SOCFPGA_CYCLONE5=y
+CONFIG_TARGET_SOCFPGA_CYCLONE5_SOCDK=y
 CONFIG_DEFAULT_DEVICE_TREE="socfpga_cyclone5_socrates"
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set