skip xinput trigger threshold check

[Kethen]

Address #18404 , remove the hard coded 30.0f/255.0f deadzone on triggers

It should be fine since analog deadzone was moved to control mapper around 633a6f6

To further address #16643 with analog mapped to digital, I'm guessing KeyMap thresholds should be evaluated (if that still happens), but this should already make it harder for analog triggers mapped to digital buttons to get stuck

ppsspp/Core/KeyMap.h

Lines 81 to 83 in 2036f1c

	const float AXIS_BIND_THRESHOLD = 0.75f;
	const float AXIS_BIND_RELEASE_THRESHOLD = 0.35f; // Used during mapping only to detect a "key-up" reliably.
	const float AXIS_BIND_THRESHOLD_MOUSE = 0.01f;

[hrydgard]

Huh, yeah, indeed forgot to remove this old deadzone handling when centralizing.

Should also just get rid of the function NormalizedDeadzoneDiffers, but I'll sneak that into the merge.