ARC: HSDK-4xD: add initial board support

Add initial HSDK-4xD board support.
The ARC HS4x/HS4xD Development Kit includes a multicore ARC HS4xD-based
chip that integrates a wide range of interfaces including Ethernet,
HDMI, WiFi, Bluetooth, USB, SDIO, I2C, SPI, UART, I2S, ADC, PWM and
GPIO, as well as a Think Silicon GPU.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/board/synopsys/hsdk/Kconfig b/board/synopsys/hsdk/Kconfig
index e8c00a6..5e23b32 100644
--- a/board/synopsys/hsdk/Kconfig
+++ b/board/synopsys/hsdk/Kconfig
@@ -9,4 +9,21 @@
 config SYS_CONFIG_NAME
 	default "hsdk"
 
+choice
+	prompt "HSDK board type"
+	default BOARD_HSDK
+
+config BOARD_HSDK
+	bool "ARC HS Development Kit"
+	help
+	  ARC HS Development Kit based on quard core ARC HS38 processor
+
+config BOARD_HSDK_4XD
+	bool "ARC HS4x/HS4xD Development Kit"
+	help
+	  ARC HS4x/HS4xD Development Kit based on quard core ARC HS48/HS47D
+	  processor
+
+endchoice
+
 endif