msm: ipa: fix rt table index and modem allignment problems

Fix two problems:
1. Change v4/v6 AP rt table starting index to be exactly the number
   of rt tables that modem uses.
2. Change modem SRAM starting address to be 8-byte alligned.

Change-Id: Iae2fe3268d5e9d7f73ff57abc8984b4344ad969e
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>