Exclude .empty and .DS_Store files in makeV2 and buildpkg

[stevezhengshiqi]

This PR will keep .empty where they are and only exclude them during zip.

Currently, makeV2 will zip the CloverV2 folder that includes .empty under CloverV2/EFI/BOOT and many other folders, resulting sym/CloverV2.zip including all these files

./CloverPackage/sym/CloverV2/EFI/CLOVER/misc/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/ACPI/origin/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/ACPI/WINDOWS/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/ACPI/patched/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/10.11/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/Other/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/11/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/10.14/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/10.13/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/10.12/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/10.15/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/12/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/13/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/14/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/kexts/Off/.empty
./CloverPackage/sym/CloverV2/EFI/CLOVER/ROM/.empty

Similarly, .DS_Store files have to be cleaned.