Removed unused PAL APIs from BSA PCIe

- Changes made in the course of porting some BSA linux tests to UEFI.
- Removed pal_pcie_scan_bridge_devices_and_check_memtype,
  pal_pcie_get_device_type and pal_smmu_max_pasids
  implementations from bsa-acs-drv.

Signed-off-by: Srikar Josyula <srikar.josyula@arm.com>