AP_GPS: SBF report correct satellite count on NrSV DNU value #8

Job	Run time
build (stm32f7, chibios, 10)	14m 38s
build (stm32h7, chibios, 10)	13m 5s
build (fmuv2-plane, chibios, 10)	6m 0s
build (periph-build, chibios, 10)	19m 49s
build (iofirmware, chibios, 10)	2m 54s
build (CubeOrange-bootloader, chibios, 10)	1m 9s
build (fmuv3-bootloader, chibios, 10)	1m 15s
build (revo-bootloader, chibios, 10)	2m 0s
build (stm32h7-debug, chibios, 10)	7m 1s
build (fmuv3, chibios, 10)	13m 29s
build (revo-mini, chibios, 10)	10m 38s
build (MatekF405-Wing, chibios, 10)	11m 23s
build (CubeOrange-ODID, chibios, 10)	8m 21s
build (CubeRedPrimary-bootloader, chibios, 10)	1m 13s
build (configure-all, chibios, 10)	9m 36s
build (build-options-defaults-test, chibios, 10)	19m 56s
build (signing, chibios, 10)	9m 55s
build (CubeOrange-PPP, chibios, 10)	7m 20s
build (CubeOrange-SOHW, chibios, 10)	7m 6s
build (Pixhawk6X-PPPGW, chibios, 10)	3m 19s
	2h 50m 7s

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