m68k: mac: Remove unused sine_data[]

When building with W=1:

    arch/m68k/mac/macboing.c:29:26: warning: ‘sine_data’ defined but not used [-Wunused-const-variable=]
       29 | static const signed char sine_data[] = {
	  |                          ^~~~~~~~~

The predefined sine table was superseded by a table calculated at
run-time in v2.2.0.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/75dbc0a141490daf9febfb8cb4a43ae87fbe3352.1694613528.git.geert@linux-m68k.org