cairo: add missing MAINTAINERS file

This removes the following two warnings from buildman:

	WARNING: no status info for 'cairo'
	WARNING: no maintainers for 'cairo'

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>

board/quipos/cairo/MAINTAINERS

@@ -0,0 +1,6 @@
+CAIRO BOARD
+M:	Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
+S:	Maintained
+F:	board/quipos/cairo/
+F:	include/configs/omap3_cairo.h
+F:	configs/cairo_defconfig