soc/amd/*/data_fabric: use DF_ prefix for bit and shift defines

soc/amd/*/data_fabric: use DF_ prefix for bit and shift defines

Adding the DP_ prefix to the defines for MMIO_NP, MMIO_WE and MMIO_RE
clarifies the scope of those definitions. For consistency also add this
prefix to MMIO_DST_FABRIC_ID_SHIFT.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I3a509ccc071aa51a67552fb9e7195358a76fe4dc
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59627
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>