configure.ac: enable_asm=yes when x-compiling across same X86 arch

configure.ac: enable_asm=yes when x-compiling across same X86 arch

Currently, configure script is forcing 'enable_asm' to be 'no'
whenever cross-compilation is performed on X86 host. This is
based on an assumption that target architecture is different
from host's (i.e. ARM). But there's always a case that we do
cross-compilation for target that is also X86 based just like
host in which same ASM codes will be supported. 'enable_asm'
should not be forced to be "no" anymore in this case.

v2: corrected commit message

Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>