soc: bcm: brcmstb: Fix re-entry point with a THUMB2_KERNEL

soc: bcm: brcmstb: Fix re-entry point with a THUMB2_KERNEL

BugLink: https://bugs.launchpad.net/bugs/1854975
[ Upstream commit fb14ada11d62fb849fc357a25ef8016ba438ba10 ]

When the kernel is built with CONFIG_THUMB2_KERNEL we would set the
kernel's resume entry point to be a function that is already built as
Thumb-2 code while the boot agent doing the resume is in ARM mode, so
this does not work. There is a header label defined: cpu_resume_arm
which we can use to do the switching for us.

Fixes: 0b741b8234c8 ("soc: bcm: brcmstb: Add support for S2/S3/S5 suspend states (ARM)")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>