sh: add earlycon support to j2_defconfig

Signed-off-by: Rich Felker <dalias@libc.org>
diff --git a/arch/sh/configs/j2_defconfig b/arch/sh/configs/j2_defconfig
index 530e66e..2eb81ebe 100644
--- a/arch/sh/configs/j2_defconfig
+++ b/arch/sh/configs/j2_defconfig
@@ -21,6 +21,7 @@
 CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_NETDEVICES=y
+CONFIG_SERIAL_EARLYCON=y
 CONFIG_SERIAL_UARTLITE=y
 CONFIG_SERIAL_UARTLITE_CONSOLE=y
 CONFIG_I2C=y