configs: add Qemu nios2 defconfig

Tested with Qemu the latest master (upcoming 2.9 release)

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/qemu/nios2-10m50/linux-4.9.fragment

@@ -0,0 +1,3 @@
+# Embed the DTB in the kernel image
+CONFIG_NIOS2_DTB_SOURCE_BOOL=y
+CONFIG_NIOS2_DTB_SOURCE="arch/nios2/boot/dts/10m50_devboard.dts"

board/qemu/nios2-10m50/readme.txt

@@ -0,0 +1,9 @@
+Run the emulation with:
+
+  qemu-system-nios2 -kernel output/images/vmlinux -nographic
+
+The login prompt will appear in the terminal that started Qemu.
+
+Tested with the upcoming QEMU 2.9.0 [1]
+
+[1] http://git.qemu.org/?p=qemu.git;h=ae5045ae5b2bbd8ce1335d1b05f9ecacca83a6cf

configs/qemu_nios2_10m50_defconfig

@@ -0,0 +1,7 @@
+BR2_nios2=y
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.9.5"
+BR2_LINUX_KERNEL_DEFCONFIG="10m50"
+BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/qemu/nios2-10m50/linux-4.9.fragment"
+BR2_TARGET_ROOTFS_INITRAMFS=y