Unify lx_emul Block bindings

[cnuke]

The following commits are going to unify the various Block bindings found in the block.c file in the ported sd_card drivers.

[nfeske]

I like this change, yet would appreciate a green light by @skalk before merging.

[skalk]

I'm fine with the consolidation work. @cnuke very nice that you eliminated the need for the legacy linux port. Only question left: can't we delete that port as well?

[cnuke]

I have not removed the port files because we might switch legacy_linux to the current 6.6.x version during the 6.12.x transition, so it could be fast-fordwarded to the current version. On the other hand we can remove it now and recreate it again when needed.

[skalk]

@cnuke thanks for the explanation. Well, I think it is more consistent and straight forward to now remove the legacy port and its patches, and later if needed to rename the linux port into legacy_linux, when adding a new one.