arc: hard-code CONFIG_ARCH_EARLY_INIT_R in asm/config.h

Common arch_early_init_r() is used in "arc/lib/cpu.c" for all ARC boards
so there's no sense in separate per-board definitions.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/arch/arc/include/asm/config.h b/arch/arc/include/asm/config.h
index c1e9b44..b4e9099 100644
--- a/arch/arc/include/asm/config.h
+++ b/arch/arc/include/asm/config.h
@@ -10,6 +10,7 @@
 #define CONFIG_SYS_GENERIC_BOARD
 #define CONFIG_SYS_GENERIC_GLOBAL_DATA
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
+#define CONFIG_ARCH_EARLY_INIT_R
 
 #define CONFIG_LMB