refactor(fvp): align the NV counter naming

Align the naming of nv_counter to nv_ctr in the DTBs
so that they match with the static C files. Update the
binding documentation accordingly. This renaming is beneficial
for the upcoming conversion tool that will convert CoT DT files
to C files.

Change-Id: If65d51ad9fc6445b1ae9937f1691becf8742cf01
Signed-off-by: Xialin Liu <Xialin.Liu@ARM.com>
4 files changed