cpufreq: brcmstb-avs-cpufreq: Fix initial command check

cpufreq: brcmstb-avs-cpufreq: Fix initial command check

BugLink: https://bugs.launchpad.net/bugs/1863019
[ Upstream commit 22a26cc6a51ef73dcfeb64c50513903f6b2d53d8 ]

There is a logical error in brcm_avs_is_firmware_loaded() whereby if the
firmware returns -EINVAL, we will be reporting this as an error. The
comment is correct, the code was not.

Fixes: de322e085995 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for Broadcom STB SoCs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>