MAINTAINERS: Add me as reviewer of overall accelerators section

I'd like to be informed of overall changes of accelerators.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250703173248.44995-40-philmd@linaro.org>

Author: philmd

MAINTAINERS

@@ -495,6 +495,7 @@ Guest CPU Cores (other accelerators)
 Overall
 M: Richard Henderson <richard.henderson@linaro.org>
 R: Paolo Bonzini <pbonzini@redhat.com>
+R: Philippe Mathieu-Daudé <philmd@linaro.org>
 S: Maintained
 F: include/exec/cpu*.h
 F: include/exec/target_long.h