MAINTAINERS: Update Kirill Shutemov's email address for TDX

Update MAINTAINERS to use my @kernel.org email address.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20250708101922.50560-4-kirill.shutemov%40linux.intel.com

Author: kiryl

.mailmap

@@ -416,6 +416,7 @@ Kenneth W Chen <kenneth.w.chen@intel.com>
 Kenneth Westfield <quic_kwestfie@quicinc.com> <kwestfie@codeaurora.org>
 Kiran Gunda <quic_kgunda@quicinc.com> <kgunda@codeaurora.org>
 Kirill Tkhai <tkhai@ya.ru> <ktkhai@virtuozzo.com>
+Kirill A. Shutemov <kas@kernel.org> <kirill.shutemov@linux.intel.com>
 Kishon Vijay Abraham I <kishon@kernel.org> <kishon@ti.com>
 Konrad Dybcio <konradybcio@kernel.org> <konrad.dybcio@linaro.org>
 Konrad Dybcio <konradybcio@kernel.org> <konrad.dybcio@somainline.org>

MAINTAINERS

@@ -26944,7 +26944,7 @@ F:	arch/x86/kernel/stacktrace.c
 F:	arch/x86/kernel/unwind_*.c
 
 X86 TRUST DOMAIN EXTENSIONS (TDX)
-M:	Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+M:	Kirill A. Shutemov <kas@kernel.org>
 R:	Dave Hansen <dave.hansen@linux.intel.com>
 L:	x86@kernel.org
 L:	linux-coco@lists.linux.dev