configs: ethernut5: Drop reiserfs

This is the only board that enables it, and looking generally I don't
believe it's used. All use cases I could fine for the board rub by
default off jffs on the nand and it doesn't enable USB storage.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Cc: egnite GmbH <info@egnite.de>
diff --git a/configs/ethernut5_defconfig b/configs/ethernut5_defconfig
index bdd8f4d..cc2f567 100644
--- a/configs/ethernut5_defconfig
+++ b/configs/ethernut5_defconfig
@@ -53,7 +53,6 @@
 CONFIG_CMD_MTDPARTS=y
 CONFIG_MTDIDS_DEFAULT="nand0=atmel_nand"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=atmel_nand:-(root)"
-CONFIG_CMD_REISER=y
 CONFIG_CMD_UBI=y
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y