Merge branch 'net-ipa-fix-HOLB-timer-register-use'

Alex Elder says:

====================
net: ipa: fix HOLB timer register use

The function ipa_reg_init_hol_block_timer_val() generates the value
to write into the HOL_BLOCK_TIMER endpoint configuration register,
to represent a given timeout value (in microseconds).  It only
supports a timer value of 0 though, in part because that's
sufficient, but mainly because there was some confusion about
how the register is formatted in newer hardware.

I got clarification about the register format, so this series fixes
ipa_reg_init_hol_block_timer_val() to work for any supported delay
value.

The delay is based on the IPA core clock, so determining the value
to write for a given period requires access to the current core
clock rate.  So the first patch just creates a new function to
provide that.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>