HID: playstation: fix array size comparison (off-by-one)

The comparison of value with the array size ps_gamepad_hat_mapping
appears to be off-by-one. Fix this by using >= rather than > for the
size comparison.

Addresses-Coverity: ("Out-of-bounds read")
Fixes: bc2e15a9 ("HID: playstation: initial DualSense USB support.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>