ARM: OMAP: PM: Lock clocks list while generating summary

ARM: OMAP: PM: Lock clocks list while generating summary

Commit b29948f9eb5e2420411763a32d2177d56fdbe6ba (OMAP: Add debugfs
node to show the summary of all clocks) introduced clock summary,
however, we are interested in seeing snapshot of the clock state, not
in dynamically changing clock configurations as the data provided by
clock summary will then be useless for debugging configuration
issues. So, hold the common lock when dumping the clock summary.

Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[nm@ti.com: added commit message]
Signed-off-by: Nishanth Menon <nm@ti.com>
[paul@pwsan.com: minor edits to commit message]
Signed-off-by: Paul Walmsley <paul@pwsan.com>