net: ipa: add IPA v5.0 GSI register definitions

Add the definitions of GSI register offsets and fields for IPA v5.0.
These are used for the SDX65 SoC.  Increase the maximum channel and
event ring counts supported by the driver, so those implemented by
the SDX65 are supported.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>