x86/ac3dsp_init: try to workaround ICC failure.

The asm code is not valid for older compilers as it uses too many
operands, ICC on x86_32 seems affected by this.
This patch disables the affected code for ICC on x86_32 and should
make it compileable again.
A better fix would be to use fewer operands or to change this code
to yasm, later is being worked on AFAIK so this is a temporary
solution.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
