wimax/i2400m: add missing debug submodule definition

The i2400m driver was missing the definition for the sysfs debug
level, which is declared in debug-levels.h.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>

drivers/net/wimax/i2400m/driver.c

@@ -785,6 +785,7 @@ struct d_level D_LEVEL[] = {
 	D_SUBMODULE_DEFINE(netdev),
 	D_SUBMODULE_DEFINE(rfkill),
 	D_SUBMODULE_DEFINE(rx),
+	D_SUBMODULE_DEFINE(sysfs),
 	D_SUBMODULE_DEFINE(tx),
 };
 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);