libcxgb: remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.
Signed-off-by: NWei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/libcxgb/libcxgb_ppm.c

@@ -39,7 +39,6 @@
 #define pr_fmt(fmt) DRV_NAME ": " fmt
 
 #include <linux/kernel.h>
-#include <linux/version.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/types.h>