[IMPORTANT] Add support for dual analog control to Analog Controller (DualShock) (currently only the left thumbstick works)

[davidhedlund]

While other PlayStation Libretro cores support dual analog control, Swanstation only support the left thumbstick, leaving the right thumbstick inoperative.

This limitation breaks the game experience in a few games that utilize dual analog control schemes, such as Tomb Raider III: Adventures of Lara Croft (right thumbstick is used for camera mode), that I used to evaluate the thumbstick as shown in the table below:

Core	Device Type	Left thumbstick works	Right thumbstick works
Beetle PSX	DualShock	Yes	Yes
Beetle PSX	Analog Controller	Yes	Yes
Beetle PSX HW	DualShock	Yes	Yes
Beetle PSX HW	Analog Controller	Yes	Yes
PCSX ReARMed	dualshock	Yes	Yes
Swanstation	Analog Controller (DualShock)	Yes	No