test/power: fix 32-bit build

test/power: fix 32-bit build

Compilation issue:

test/test/test_power_acpi_cpufreq.c:556:31:
error: format ‘%lx’ expects argument of type ‘long unsigned int’,
but argument 2 has type ‘uint64_t {aka long long unsigned int}’

  printf("ACPI: Capabilities %lx\n", caps.capabilities);
                             ~~^     ~~~~~~~~~~~~~~~~~
                             %llx

Fixes: 39e38d583075 ("test/power: add unit test for get capabilities API")
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Radu Nicolau <radu.nicolau@intel.com>