arm: Properly match /* */ comments in the arm assembly

Some versions of the clang built-in assembler interprets /* as a start
of a multi-line comment, even within lines starting with a @. Therefore,
make sure to terminate these properly.

This fixes warnings about /* within a block comment when building
using the clang built-in assembler (in some versions of clang), and
fixes issues where part of the assembly source was effectively
commented out, when building with this assembler.

Change-Id: I4b520334d92740f8c60def94ee990561b2cb8b7c
8 files changed