MAINTAINERS: Add entry for common entry code

Signed-off-by: Thomas Gleixner <[e-mail]>

MAINTAINERS

···
 F:	drivers/base/arch_topology.c
 F:	include/linux/arch_topology.h
 
+GENERIC ENTRY CODE
+M:	Thomas Gleixner <[e-mail]>
+M:	Peter Zijlstra <[e-mail]>
+M:	Andy Lutomirski <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/entry
+F:	include/linux/entry-common.h
+F:	include/linux/entry-kvm.h
+F:	kernel/entry/
+
 GENERIC GPIO I2C DRIVER
 M:	Wolfram Sang <[e-mail]>
 S:	Supported