msm: pcie: add support for varying PCIe PHY status bit

Status bit for PCIe PHY varies for each PCIe core. Add
the support to check the correct status bit for each
of them. Update sa8155 and sm8150 with PCIe PHY status
bit.

Change-Id: Iba583eeb3ef41c12381bee7ff2d6dd1d4cdb5fba
Signed-off-by: Tony Truong <truong@codeaurora.org>