Fix bug in ATMega sine computation #879

Job	Run time
Test compiling (arduino:avr:uno)	2m 4s
lint	4s
Test compiling (arduino:sam:arduino_due_x)	38s
Test compiling (arduino:avr:mega)	27s
Test compiling (arduino:avr:leonardo)	20s
Test compiling (arduino:samd:nano_33_iot)	52s
Test compiling (adafruit:samd:adafruit_metro_m4)	1m 32s
Test compiling (esp32:esp32:esp32doit-devkit-v1)	3m 42s
Test compiling (esp32:esp32:esp32s2)	2m 20s
Test compiling (esp32:esp32:esp32s3)	2m 27s
Test compiling (STMicroelectronics:stm32:GenF1:pnum=BLUEPILL_F103C8)	2m 47s
Test compiling (STMicroelectronics:stm32:Nucleo_64:pnum=NUCLEO_F411RE)	5m 23s
Test compiling (STMicroelectronics:stm32:GenF4:pnum=GENERIC_F405RGTX)	2m 30s
Test compiling (STMicroelectronics:stm32:GenL4:pnum=GENERIC_L475RGTX)	6m 7s
Test compiling (STMicroelectronics:stm32:Disco:pnum=B_G431B_ESC1)	1m 10s
Test compiling (arduino:mbed_rp2040:pico)	58s
	33m 21s

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