PCI: qcom: Remove PCIE20_ prefix from register definitions

The PCIE part is redundant and 20 doesn't represent anything across the
SoCs supported now. So let's get rid of the prefix.

This involves adding the IP version suffix to one definition of
PARF_SLV_ADDR_SPACE_SIZE that defines offset specific to that version.
The other definition is generic for the rest of the versions.

Also, the register PCIE20_LNK_CONTROL2_LINK_STATUS2 is not used anywhere,
hence removed.

Link: https://lore.kernel.org/r/20230316081117.14288-3-manivannan.sadhasivam@linaro.orgSigned-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>