os-support/solaris: Set IOPL for input thread too

Since the Solaris kernel tracks IOPL per thread, and doesn't inherit
raised IOPL levels when creating a new thread, we need to turn it on
in the input thread for input drivers like vmmouse that need register
access to work correctly.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
(cherry picked from commit 12769c516d)

hw/xfree86/os-support/solaris/sun_vid.c

@@ -76,7 +76,11 @@ xf86OSInitVidMem(VidMemInfoPtr pVidMem)
 void
 xf86OSInputThreadInit()
 {
-    return;
+    /*
+     * Need to enable in input thread as well, as Solaris kernel tracks
+     * IOPL per-thread and doesn't inherit when creating a new thread.
+     */
+    xf86EnableIO();
 }
 
 Bool