"PlayStation" or "xbox" layout has never been referred to merely the face buttons until now.
What is meant by "layout" is... Well... The layout. Where the buttons and the sticks are. The PlayStation layout is symmetrical. The xbox layout is lopsided, with the left stick abd the d-pad switched around.
A lot less talked about is also the Gamecube layout, again not merely referring to the style of face buttons but their physical layout.