eal: fix tsc frequency

eal: fix tsc frequency

Fix error where TSC freq is 0.

The logical OR operator evaluates to 1 if any of its operands is
different than 0.

Error showed later while initializing PMD:
EAL: TSC frequency is ~0 KHz
<snip>
PMD: eth_ixgbe_dev_init(): Hardware Initialization Failure: -30
EAL: Error - exiting with code: 1
  Cause: Requested device 0000:84:00.0 cannot be used

Fixes: 040cf8a41187 ("eal: deduplicate timer functions")

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
Acked-by: John McNamara <john.mcnamara@intel.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>