broadcom-wl: fix compilation with kernel 5.4

This adds two fixes for compilation with kernel 5.4:

1. dev_open from include/linux/netdevice.h needs a second parameter
   since kernel 5.0:
   00f54e68924e ("net: core: dev: Add extack argument to dev_open()")
2. get_ds() macro definition has been dropped since kernel 5.1:
   736706bee329 ("get rid of legacy 'get_ds()' function")
   Since get_ds() has been just a macro before, replace it in
   the driver instead of creating a version switch.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

package/kernel/broadcom-wl/patches/916-fix-compilation-for-5_4.patch

@@ -0,0 +1,18 @@
+--- a/driver/wl_iw.c
++++ b/driver/wl_iw.c
+@@ -112,10 +112,14 @@
+ 	ifr.ifr_data = (caddr_t) &ioc;
+ 
+ 	/* Must be up for virtually all useful ioctls */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
++	dev_open(dev, NULL);
++#else
+ 	dev_open(dev);
++#endif
+ 
+ 	fs = get_fs();
+-	set_fs(get_ds());
++	set_fs(KERNEL_DS);
+ 	ret = dev->netdev_ops->ndo_do_ioctl(dev, &ifr, SIOCDEVPRIVATE);
+ 	set_fs(fs);
+