[...]

#if [ "$CARCH" = "x86_64" ]; then
#  source=('acpi_call-x86_64.patch')
#  sha1sums=('2cfb22deca7687b87d3cbd06dbd1d59e73210f62')
#fi

[...]

 ## x86_64 Patch
 # if [ "$CARCH" = "x86_64" ]; then
 #     msg "Patching for x86_64 systems"
 #     patch -p1 -i ${srcdir}/acpi_call-x86_64.patch
 # fi  

[...]