perf machine: Introduce machine__find_kernel_symbol_by_name()

perf machine: Introduce machine__find_kernel_symbol_by_name()

To be used in the 'vmlinux matches kallsyms' 'perf test'  entry.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>