MAINTAINERS: Update email address for Sean Christopherson

Update my email address to one provided by my new benefactor.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: kvm@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20201119183707.291864-1-sean.kvm@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

.mailmap

@@ -287,6 +287,7 @@ Santosh Shilimkar <ssantosh@kernel.org>
 Sarangdhar Joshi <spjoshi@codeaurora.org>
 Sascha Hauer <s.hauer@pengutronix.de>
 S.Çağlar Onur <caglar@pardus.org.tr>
+Sean Christopherson <seanjc@google.com> <sean.j.christopherson@intel.com>
 Sean Nyekjaer <sean@geanix.com> <sean.nyekjaer@prevas.dk>
 Sebastian Reichel <sre@kernel.org> <sebastian.reichel@collabora.co.uk>
 Sebastian Reichel <sre@kernel.org> <sre@debian.org>