test/timer: replace config macro with runtime log level

This patch replaces macro with log-level based approach to print debug
information. Need to set timer log type to debug  using the following
eal parameter: --log-level=test.timer:debug

Suggested-by: Thomas Monjalon <thomas@monjalon.net>
Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>