cpufreq: imx6q: Don't disable 792 Mhz OPP unnecessarily

stable inclusion
from stable-v6.6.5
commit 59fe58d59070e60ea938f8d6d5435e85d16d9a71
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8N21P

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=59fe58d59070e60ea938f8d6d5435e85d16d9a71

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[ Upstream commit 2e4e0984c7d696cc74cf2fd7e7f62997f0e9ebe6 ]

For a 900MHz i.MX6ULL CPU the 792MHz OPP is disabled. There is no
convincing reason to disable this OPP. If a CPU can run at 900MHz,
it should also be able to cope with 792MHz. Looking at the voltage
level of 792MHz in [1] (page 24, table 10. "Operating Ranges") the
current defined OPP is above the minimum. So the voltage level
shouldn't be a problem. However in [2] (page 24, table 10.
"Operating Ranges"), it is not mentioned that 792MHz OPP isn't
allowed. Change it to only disable 792MHz OPP for i.MX6ULL types
below 792 MHz.

[1] https://www.nxp.com/docs/en/data-sheet/IMX6ULLIEC.pdf
[2] https://www.nxp.com/docs/en/data-sheet/IMX6ULLCEC.pdf



Fixes: 0aa9abd4 ("cpufreq: imx6q: check speed grades for i.MX6ULL")
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <festevam@denx.de>
[ Viresh: Edited subject ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>