PCI: qcom: Add missing macros for register fields

Some of the registers are changed using hardcoded bitfields without macros.
This provides no information on what the register setting is about. So add
the macros to those fields for making the code more understandable.

Link: https://lore.kernel.org/r/20230316081117.14288-6-manivannan.sadhasivam@linaro.org


Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>