net: ipa: generic command param fix

Starting at IPA v4.11, the GSI_GENERIC_COMMAND GSI register got a
new PARAMS field.  The code that encodes a value into that field
sets it unconditionally, which is wrong.

We currently only provide 0 as the field's value, so this error has
no real effect.  Still, it's a bug, so let's fix it.

Fix an (unrelated) incorrect comment as well.  Fields in the
ERROR_LOG GSI register actually *are* defined for IPA versions
prior to v3.5.1.

Fixes: fe68c43c ("net: ipa: support enhanced channel flow control")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>