net: ipa: fix some register validity checks

A recent commit defined HW_PARAM_4 as a GSI register ID but did not
add it to gsi_reg_id_valid() to indicate it's valid (for IPA v5.0+).
Add version checks for the HW_PARAM_2 and INTER_EE IRQ GSI registers
there as well.

IPA v5.0 supports up to 8 source and destination resource groups.
Update the validity check (and the comments where the register IDs
are defined) to reflect that.  Similarly update comments and
validity checks for the hash/cache-related registers.

Note that this patch fixes an omission and constrains things
further, but these don't technically represent bugs.

Fixes: f651334e ("net: ipa: add HW_PARAM_4 GSI register")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>