MAINTAINERS: Update tree for platform-drivers-x86

Update the tree listed for X86 PLATFORM DRIVERS to its new top level
reposority at infradead. The old one is an alias to the new one, but
we prefer to remove the "user/dvhart" from the URL.
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

MAINTAINERS

@@ -14863,7 +14863,7 @@ X86 PLATFORM DRIVERS
 M:	Darren Hart <dvhart@infradead.org>
 M:	Andy Shevchenko <andy@infradead.org>
 L:	platform-driver-x86@vger.kernel.org
-T:	git git://git.infradead.org/users/dvhart/linux-platform-drivers-x86.git
+T:	git git://git.infradead.org/linux-platform-drivers-x86.git
 S:	Maintained
 F:	drivers/platform/x86/
 F:	drivers/platform/olpc/