net: ipa: fix QMI structure definition bugs

Building with "W=1" did exactly what it was supposed to do, namely
point out some suspicious-looking code to be verified not to contain
bugs.

Some QMI message structures defined in "ipa_qmi_msg.c" contained
some bad field names (duplicating the "elem_size" field instead of
defining the "offset" field), almost certainly due to copy/paste
errors that weren't obvious in a scan of the code.  Fix these bugs.

Fixes: 530f9216 ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>