arm64: topology: Do not warn on missing AMU in cpuhp_topology_online()

arm64: topology: Do not warn on missing AMU in cpuhp_topology_online()

When CONFIG_CPUMASK_OFFSTACK is not enabled, and resuming from s2ram on
Renesas R-Car H3 (big.LITTLE 4x Cortex-A57 + 4x Cortex-A53), during
enabling of the first little core, a warning message is printed:

    AMU: CPU[4] doesn't support AMU counters

This confuses users, as during boot amu_fie_setup() does not print such
a message, unless debugging is enabled (freq_counters_valid() prints
"CPU%d: counters are not supported.\n" at debug level in that case).

Hence drop the warning, freq_counters_valid() has already printed a
debug message anyway.

Fixes: 6fd9be0b7b2e ("arm64: topology: Handle AMU FIE setup on CPU hotplug")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>