msm: ipa: add support to 15 PDN offload via IPA

Make changes to increase the max num hw pdns to 15 to cater
to requirement. Also increase the SRAM memory for PDN table
to store the additional PDN entries.

Change-Id: I6a0ff4659d4c577635b89e7d8d2a0de108b39269
Signed-off-by: Armaan Siddiqui <asiddiqu@codeaurora.org>