ath6kl: remove unused define NO_SYNC_FLUSH

Cc: Naveen Singh <nsingh@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ath6kl/Makefile

@@ -110,7 +110,6 @@ ifeq ($(CONFIG_ATH6KL_SKIP_ABI_VERSION_CHECK),y)
 ccflags-y += -DATH6KL_SKIP_ABI_VERSION_CHECK
 endif
 
-ccflags-y += -DNO_SYNC_FLUSH
 ccflags-y += -DHTC_EP_STAT_PROFILING
 ccflags-y += -DWAPI_ENABLE
 ccflags-y += -DCHECKSUM_OFFLOAD