Use directional macros for gamepad buttons

[TriceHelix]

Currently, the X and Y buttons on any XBox Gamepad map to BTN_X and BTN_Y. However, the Linux kernel expects X and Y to be located NORTH and WEST respectively (reference). This contradicts the physical layout of an XBox controller.

This commit simply replaces the macros BTN_A, BTN_B, BTN_X, and BTN_Y with BTN_SOUTH, BTN_EAST, BTN_WEST, and BTN_NORTH in order to fix the incorrect behaviour, effectively swapping X and Y.

I also created a PR for this on the original repo, however that seems to be more or less inactive.