net: ipa: Fix decoding EV_PER_EE for IPA v5.0+

net: ipa: Fix decoding EV_PER_EE for IPA v5.0+

Initially 'reg' and 'val' are assigned from HW_PARAM_2.

But since IPA v5.0+ takes EV_PER_EE from HW_PARAM_4 (instead of
NUM_EV_PER_EE from HW_PARAM_2), we not only need to re-assign 'reg' but
also read the register value of that register into 'val' so that
reg_decode() works on the correct value.

Fixes: f651334e1ef5 ("net: ipa: add HW_PARAM_4 GSI register")
Link: https://sashiko.dev/#/patchset/20260403-milos-ipa-v1-0-01e9e4e03d3e%40fairphone.com?part=2
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://patch.msgid.link/20260409-ipa-fixes-v1-2-a817c30678ac@fairphone.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>