msm: ipa4: Cleanup IPA registers dump

Move the macros and change the return type of the functions.
Add an if condition to include the n_registers for printing
to dmesg. Create a separate IPC log for regdumps.

Change-Id: Ic2c11eda268342277e79465a0cfb329b95bf868b
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>