soc/amd: Factor out gpp_clk_setup function

gpp_clk_setup code in most AMD SoC is similar and it can moved to common
code. The only thing which is SoC dependent in this function is the SoC
config, hence keep it in SoC code and move everything else in new
gpp_clk_setup_common function which is in soc/amd/common. Picasso and
Glinda don't have pcie_gpp_dxio_update_clk_req_config fixup function so
they are addressed in later patches.

Change-Id: I7d7da4bfe079f07e31212247dbf3acd14daa6447
Signed-off-by: Varshit Pandya <pandyavarshit@gmail.com>
---
M src/soc/amd/cezanne/Kconfig
M src/soc/amd/cezanne/fch.c
M src/soc/amd/cezanne/include/soc/southbridge.h
A src/soc/amd/common/block/gpp_clk/Kconfig
A src/soc/amd/common/block/gpp_clk/Makefile.mk
A src/soc/amd/common/block/gpp_clk/gpp_clk.c
M src/soc/amd/common/block/include/amdblocks/pci_clk_req.h
M src/soc/amd/mendocino/Kconfig
M src/soc/amd/mendocino/fch.c
M src/soc/amd/mendocino/include/soc/southbridge.h
M src/soc/amd/phoenix/Kconfig
M src/soc/amd/phoenix/fch.c
M src/soc/amd/phoenix/include/soc/southbridge.h
13 files changed, 80 insertions(+), 160 deletions(-)