broadcom-wl: Fix compilation with kernel 5.10

This adds a few fixes for compiling against Linux 5.10:

1. segment_eq() has been removed with upstream commit
   428e2976a5bf7e7f5554286d7a5a33b8147b106a ("uaccess: remove
   segment_eq") and can use uaccess_kernel() instead
2. ioremap_nocache() is removed and is now an alias for ioremap() with
   upstream commit 4bdc0d676a643140bdf17dbf7eafedee3d496a3c ("remove
   ioremap_nocache and devm_ioremap_nocache")

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

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

@@ -1,6 +1,6 @@
 --- a/driver/wl_iw.c
 +++ b/driver/wl_iw.c
-@@ -112,10 +112,14 @@
+@@ -112,10 +112,14 @@ dev_wlc_ioctl(
  	ifr.ifr_data = (caddr_t) &ioc;
  
  	/* Must be up for virtually all useful ioctls */