qca_spi: Improve reset mechanism

The commit 92717c23 ("net: qca_spi: Avoid high load if QCA7000 is not
available") fixed the high load in case the QCA7000 is not available
but introduced sync delays for some corner cases like buffer errors.

So add the reset requests to the atomics flags, which are polled by
the SPI thread. As a result reset requests and sync state are now
separated. This has the nice benefit to make the code easier to
understand.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://patch.msgid.link/20241007113312.38728-3-wahrenst@gmx.net


Signed-off-by: Jakub Kicinski <kuba@kernel.org>