eal: fix PRNG init with HPET enabled

eal: fix PRNG init with HPET enabled

When rte_rand_init is invoked, and the kernel running dpdk does not
support *getentropy, at the same time, the cpu does not support rdseed,
then rte_rand_init invoked rte_get_timer_cycles.

If HPET was enabled in the DPDK build (CONFIG_RTE_LIBEAL_USE_HPET=y) and
the system, rte_get_timer_cycles will invoke rte_get_hpet_cycles while
*eal_hpet is not available.

To fix that, use rte_get_tsc_cycles instead of rte_get_timer_cycles.

Fixes: 3f002f069612 ("eal: replace libc-based random generation with LFSR")
Cc: stable@dpdk.org
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>