fixp-arith: do not require users to include bug.h

The fixp_sin32_rad() contains a call to BUG_ON(). If users of
fixp-arith.h have not included the bug.h prior including the fixp-arith.h
the compiler will not find the BUG_ON. Thus every user of fixp-arith.h
must also include bug.h (or roll own variant of BUG_ON()).

Include bug.h from fixp-arith.h so every user of fixp-arith.h does not
need to include the bug.h prior inclusion of fixp-arith.h

Fixes: 559addc2 ("[media] fixp-arith: replace sin/cos table by a better precision one")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/Y3SgVdVey9legtX+@dc75zzyyyyyyyyyyyyydt-3.rev.dnainternet.fiSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

include/linux/fixp-arith.h

@@ -2,6 +2,7 @@
 #ifndef _FIXP_ARITH_H
 #define _FIXP_ARITH_H
 
+#include <linux/bug.h>
 #include <linux/math64.h>
 
 /*