sysutils/edk2: Add qemu_x64 and qemu_i386 as new FLAVORs of edk2

[bcran]

Summary

Instead of having a separate sysutils/uefi-edk2-qemu port, add qemu_x64
and qemu_i386 as FLAVORs of sysutils/edk2 and delete sysutils/uefi-edk2-qemu.

[bcran]

Fix summary.

[bcran]

I'm not sure how to handle the fact that qemu (OVMF) firmware can be built for both x86_64 and i386.
The existing port uses FLAVOR, but since sysutils/edk2 already uses FLAVOR for the platform, I'm not sure how selecting the architecture should be done.

[manu]

In D35408#802860, @bcran wrote:

I'm not sure how to handle the fact that qemu (OVMF) firmware can be built for both x86_64 and i386.
The existing port uses FLAVOR, but since sysutils/edk2 already uses FLAVOR for the platform, I'm not sure how selecting the architecture should be done.

Add two flavors, one qemu_x86 and one qemu_i386

[bcran]

Add separate qemu_x64 and qemu_i386 flavors.

[manu]

Since it depends on nasm I think it needs an ONLY_FOR_ARCH and the old one seems to be restricted on amd64 only.

[bcran]

Add ONLY_FOR_ARCH lines and revert i386 addition at top