net: ipa: support more versions for HOLB timer

IPA version 3.5.1 represents the timer used in avoiding head-of-line
blocking with a simple tick count.  IPA v4.2 changes that, instead
splitting the timer field into two parts (base and scale) to
represent the ticks in the timer period.

IPA v4.0 and IPA v4.1 use the same method as IPA v3.5.1.  Change the
test in ipa_reg_init_hol_block_timer_val() so the result is correct
for those versions as well.

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