configs: add ARC HS38 VDK virtual boards

Virtualizer Development Kits (VDKs) are software development kits
containing design-specific virtual prototypes as well as debug and
analysis tools and sample software.

With this change we add support for VDK based on ARC HS38 core.

Note that FS-overlay is required to allow instantiation of console on
both serial port and LCD screen simultaneously.

Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

configs/snps_hs38_smp_vdk_defconfig

@@ -0,0 +1,21 @@
+# Architecture
+BR2_arcle=y
+BR2_archs38=y
+
+# System
+BR2_TARGET_GENERIC_HOSTNAME="hs38_vdk"
+BR2_TARGET_GENERIC_ISSUE="Welcome to the HS38 VDK Software Development Platform"
+BR2_ROOTFS_OVERLAY="board/synopsys/axs10x/fs-overlay"
+BR2_TARGET_ROOTFS_EXT2=y
+
+# Headers
+BR2_KERNEL_HEADERS_VERSION=y
+BR2_DEFAULT_KERNEL_VERSION="4.2"
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_2=y
+
+# Kernel
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.2"
+BR2_LINUX_KERNEL_DEFCONFIG="vdk_hs38_smp"
+BR2_LINUX_KERNEL_VMLINUX=y

configs/snps_hs38_vdk_defconfig

@@ -0,0 +1,21 @@
+# Architecture
+BR2_arcle=y
+BR2_archs38=y
+
+# System
+BR2_TARGET_GENERIC_HOSTNAME="hs38_vdk"
+BR2_TARGET_GENERIC_ISSUE="Welcome to the HS38 VDK Software Development Platform"
+BR2_ROOTFS_OVERLAY="board/synopsys/axs10x/fs-overlay"
+BR2_TARGET_ROOTFS_EXT2=y
+
+# Headers
+BR2_KERNEL_HEADERS_VERSION=y
+BR2_DEFAULT_KERNEL_VERSION="4.2"
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_2=y
+
+# Kernel
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.2"
+BR2_LINUX_KERNEL_DEFCONFIG="vdk_hs38"
+BR2_LINUX_KERNEL_VMLINUX=y