net: wwan: iosm: Remove DEBUG flag

Author forgot to remove that flag.

Fixes: f7af616 ("net: iosm: infrastructure")
Reported-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wwan/iosm/Makefile

@@ -21,6 +21,3 @@ iosm-y = \
 	iosm_ipc_mux_codec.o
 
 obj-$(CONFIG_IOSM) := iosm.o
-
-# compilation flags
-ccflags-y += -DDEBUG