Optimise in-game atad driver for size #1310

Job	Run time
build-lang	50s
build	1m 13s
build-debug (debug)	1m 14s
build-debug (iopcore_debug)	1m 11s
build-debug (ingame_debug)	1m 29s
build-debug (deci2_debug)	1m 8s
build-debug (eesio_debug)	1m 9s
build-variants (RTL=0, PADEMU=0, IGS=0, DTL_T10000=0)	1m 5s
build-variants (RTL=0, PADEMU=0, IGS=0, DTL_T10000=1)	1m 2s
build-variants (RTL=0, PADEMU=0, IGS=1, DTL_T10000=0)	1m 20s
build-variants (RTL=0, PADEMU=0, IGS=1, DTL_T10000=1)	1m 2s
build-variants (RTL=0, PADEMU=1, IGS=0, DTL_T10000=0)	1m 3s
build-variants (RTL=0, PADEMU=1, IGS=0, DTL_T10000=1)	1m 28s
build-variants (RTL=0, PADEMU=1, IGS=1, DTL_T10000=0)	1m 26s
build-variants (RTL=0, PADEMU=1, IGS=1, DTL_T10000=1)	1m 8s
build-variants (RTL=1, PADEMU=0, IGS=0, DTL_T10000=0)	1m 0s
build-variants (RTL=1, PADEMU=0, IGS=0, DTL_T10000=1)	1m 6s
build-variants (RTL=1, PADEMU=0, IGS=1, DTL_T10000=0)	1m 19s
build-variants (RTL=1, PADEMU=0, IGS=1, DTL_T10000=1)	1m 19s
build-variants (RTL=1, PADEMU=1, IGS=0, DTL_T10000=0)	1m 11s
build-variants (RTL=1, PADEMU=1, IGS=0, DTL_T10000=1)	1m 4s
build-variants (RTL=1, PADEMU=1, IGS=1, DTL_T10000=0)	1m 20s
build-variants (RTL=1, PADEMU=1, IGS=1, DTL_T10000=1)	1m 12s
release	0s
	27m 19s

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