arm host: fix compiler warning

arm host: fix compiler warning

Compilation for arm (native or cross) results in this
warning:

fpu/softfloat-native.c: In function ‘float64_round_to_int’:
fpu/softfloat-native.c:387: error: control reaches end of non-void function

float64_round_to_int uses special assembler code for arm
and has no explicit return value.

As there is no obvious reason why arm should need special
code, all fpu related conditionals were removed.
The remaining code is standard (C99) and compiles for arm,
too.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Acked-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>