ARC: rename default defconfig

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 10bc3d4..db72fec 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -12,7 +12,7 @@
 CROSS_COMPILE := arc-linux-uclibc-
 endif
 
-KBUILD_DEFCONFIG := fpga_defconfig
+KBUILD_DEFCONFIG := nsim_700_defconfig
 
 cflags-y	+= -mA7 -fno-common -pipe -fno-builtin -D__linux__