AP_MotorsHeli_Swash: remove uneeded constrains #332

Job	Run time
build (stm32f7, chibios, 10)	16m 8s
build (stm32h7, chibios, 10)	14m 33s
build (fmuv2-plane, chibios, 10)	7m 54s
build (periph-build, chibios, 10)	14m 17s
build (iofirmware, chibios, 10)	5m 5s
build (CubeOrange-bootloader, chibios, 10)	3m 40s
build (fmuv3-bootloader, chibios, 10)	3m 21s
build (revo-bootloader, chibios, 10)	3m 17s
build (stm32h7-debug, chibios, 10)	9m 7s
build (fmuv3, chibios, 10)	16m 5s
build (revo-mini, chibios, 10)	12m 33s
build (MatekF405-Wing, chibios, 10)	13m 28s
build (CubeOrange-ODID, chibios, 10)	10m 22s
build (CubeRedPrimary-bootloader, chibios, 10)	3m 24s
build (configure-all, chibios, 10)	12m 36s
build (build-options-defaults-test, chibios, 10)	28m 31s
build (signing, chibios, 10)	11m 36s
build (CubeOrange-PPP, chibios, 10)	9m 14s
build (SOHW, chibios, 10)	14m 38s
build (Pixhawk6X-PPPGW, chibios, 10)	5m 21s
build (new-check, chibios, 10)	15m 55s
	3h 51m 5s

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