clk: Fix JSON output in debugfs

key/value pairs in a JSON object must be separated by a comma.
After adding the properties "accuracy" and "phase" the JSON output
of /sys/kernel/debug/clk/clk_dump is invalid.

So add the missing commas to fix it.

Fixes: 5279fc40 ("clk: add clk accuracy retrieval support")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
[sboyd@codeaurora.org: Added comment in function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>