mailmap: add entry for Bence Csókás

I will be leaving Prolan this week.  You can reach me by my personal email
for now.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Bence Csókás <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: bence98

.mailmap

@@ -134,6 +134,7 @@ Ben M Cahill <[email protected]>
 Ben Widawsky <[email protected]> <[email protected]>
 Ben Widawsky <[email protected]> <[email protected]>
 Ben Widawsky <[email protected]> <[email protected]>
+Bence Csókás <[email protected]> <[email protected]>
 Benjamin Poirier <[email protected]> <[email protected]>
 Benjamin Tissoires <[email protected]> <[email protected]>
 Benjamin Tissoires <[email protected]> <[email protected]>