Debug Sequences: <debug-vars> element deprecate pname.

[ReinhardKeil]

The <debug-sequence> element has pname that allows to specify if a sequence should be executed or not.

for such a sequence may be defined, but actually not used. Having pname also in complicates the handling of configuration information from the users perspective. It is better to make the usage of the variables clear in the *.dbgconf file instead.

See also: Open-CMSIS-Pack/devtools#1947 + Open-CMSIS-Pack/devtools#1946