msm: pcie: provide userspace control to PCIe boot configuration

Users can invert the default settings for L0s, L1, L1ss,
or AER for each root complex before boot. Users can
also requests for each root complex to keep its
resources on when link training fails.

Change-Id: Id2e7617f23434e6d38f7adc89f4910c928d27edc
Signed-off-by: Tony Truong <truong@codeaurora.org>