riscv: Remove unused define in maix header

This define was left over from a previous revision, and was never used.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
diff --git a/include/configs/sipeed-maix.h b/include/configs/sipeed-maix.h
index 08acb25..4c1ff98 100644
--- a/include/configs/sipeed-maix.h
+++ b/include/configs/sipeed-maix.h
@@ -18,9 +18,6 @@
 /* Don't relocate into AI ram since it isn't set up yet */
 #define CONFIG_SYS_SDRAM_SIZE (SZ_4M + SZ_2M)
 
-/* For early init */
-#define K210_SYSCTL_BASE 0x50440000
-
 #ifndef CONFIG_EXTRA_ENV_SETTINGS
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	"loadaddr=0x80060000\0" \