arc-bridge: Send correctly-sized struct input_event
arc-bridge: Send correctly-sized struct input_event

ARC runs in 32-bits in x86_64, so the struct input_event sent in the ARC
input bridge are the wrong size.

BUG=574950
TEST=Input works in x86_64

Review URL: https://codereview.chromium.org/1565583004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#367968}

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