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.

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