gdb: Add Felix Willgerodt as the x86 architecture maintainer

This includes both the i386 and x86-64 architectures.
diff --git a/gdb/MAINTAINERS b/gdb/MAINTAINERS
index 50ad259..457dd40 100644
--- a/gdb/MAINTAINERS
+++ b/gdb/MAINTAINERS
@@ -346,6 +346,7 @@
 	h8300		--target=h8300-elf
 
 	i386		--target=i386-elf
+			Felix Willgerodt	felix.willgerodt@intel.com
 
 	ia64		--target=ia64-linux-gnu
 			(--target=ia64-elf broken)
@@ -421,6 +422,7 @@
 	vax		--target=vax-netbsd
 
 	x86-64		--target=x86_64-linux-gnu
+			Felix Willgerodt	felix.willgerodt@intel.com
 
 	xstormy16	--target=xstormy16-elf
 	xtensa		--target=xtensa-elf