trace: proftool: dump-ftrace should write funcgraph times in ns not us

trace: proftool: dump-ftrace should write funcgraph times in ns not us

When converting a U-Boot trace records file to ftrace function graph
format for use by trace-cmd ('proftool -f funcgraph dump-ftrace'), the
time associated to each function is incorrectly saved in microseconds
instead of nanoseconds. Multuply the value by 1000 to fix the issue.

With this change, the trace-cmd output looks consistent. Here is an
example with udelay(25) added to mem_malloc_init() as a test case:

 $ ./tools/proftool -m System.map -t /tmp/trace.bin -f funcgraph \
                    dump-ftrace -o /tmp/trace.dat
 $ trace-cmd report  /tmp/trace.dat >/tmp/trace.log
 $ vi /tmp/trace.log
 [...]
 u-boot-1     [000]     6.719659: funcgraph_entry:                   |    mem_malloc_init() {
 u-boot-1     [000]     6.719659: funcgraph_entry:                   |      udelay() {
 u-boot-1     [000]     6.719660: funcgraph_entry:                   |        schedule() {
 u-boot-1     [000]     6.719660: funcgraph_entry:                   |          cyclic_run() {
 u-boot-1     [000]     6.719660: funcgraph_entry:        1.000 us   |            cyclic_get_list();
 u-boot-1     [000]     6.719661: funcgraph_exit:         1.000 us   |            }
 u-boot-1     [000]     6.719661: funcgraph_exit:         1.000 us   |          }
 u-boot-1     [000]     6.719661: funcgraph_entry:                   |        __udelay() {
 u-boot-1     [000]     6.719662: funcgraph_entry:        0.000 us   |          usec_to_tick();
 u-boot-1     [000]     6.719687: funcgraph_exit:       + 26.000 us  |          }
 u-boot-1     [000]     6.719687: funcgraph_exit:       + 28.000 us  |        }
 u-boot-1     [000]     6.719687: funcgraph_entry:      # 37971.000 us |      memset();
 u-boot-1     [000]     6.757658: funcgraph_exit:       # 37999.000 us |      }
 u-boot-1     [000]     6.757658: funcgraph_exit:       # 38000.000 us |    }

In the above dump, the udelay() call is reported as taking 26 us which
is consistent with the timestamps (6.719687 - 6.719659 = 0.000026).
Without this patch we would have "0.026 us" instead of "+ 26.000 us".

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>