trace: rename kernel enum section to eval

The kernel and its modules have sections containing the enum
string to value conversions. Rename this section because we
intend to store more than enums in it.

Link: http://lkml.kernel.org/r/20170531215653.3240-2-jeremy.linton@arm.com



Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>