wcnss: Fix the copyright year for wcnss_vreg.c

The copyright year for the original file was 2011-2012; but that was
incorrectly recorded as 2012 while the file was renamed from
wcnss_riva.c to wcnss_vreg.c to support Pronto.

Change-Id: Ice5c84cc13390c6aa47d07731dfa2f3cafe99d54
Signed-off-by: Sameer Thalappil <sameert@codeaurora.org>