platform/x86: Add include/linux/platform_data/x86 to MAINTAINERS

Most of the files there are being used under PDx86 subsystem or
tightly related drivers (like drivers/clk/x86/). I think it makes
sense to assure that PDx86 keeps an eye on the changes there.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230206150202.27892-1-andriy.shevchenko@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

MAINTAINERS

@@ -22650,6 +22650,7 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git
 F:	drivers/platform/olpc/
 F:	drivers/platform/x86/
+F:	include/linux/platform_data/x86/
 
 X86 PLATFORM DRIVERS - ARCH
 R:	Darren Hart <dvhart@infradead.org>