Syn­tax Change for De­vice Tree Over­lays source file

Start­ing with the socf­p­ga-4.12 and (some ltsi branch) branch­es, a small syn­tax change will be re­quired in De­vice Tree Over­lay source (dts) files. Nor­mal dts files do not re­quire any change, only dts files that are over­lays.

The change is:

-/dts-v1/ /plugin/;
+/dts-v1/;
+/plugin/;

Without this change, the dtc will com­plain dur­ing com­pi­la­tion not­ing that char­ac­ters 10-18 on that line of the file are in­valid, such as:

Error: /home/atull/repos/linux-socfpga/arch/arm/boot/dts/persona0.dts:1.10-18 syntax error

The rea­son for this change is that plu­g­in sup­port has been of­fi­cial­ly added in the De­vice Tree Com­pil­er (dtc). We no longer have to up date the dtc with a down­stream patched ver­sion to get that func­tion­al­i­ty. The de­vice tree com­mu­ni­ty set­tled on this syn­tax, so the up­stream has this change.