pinctrl: SPEAr1310: Separate out pci pins from pcie_sata pin group

SPEAr1310 has separate PCI and PCIe implementations which are not muxed with
each other. Presently they have been implemented as muxed together with SATA and
are represented wrongly in the software.

In reality only PCIe and SATA implementations are muxed with each other. This
patch separates out pci pins creating a new pingroup and function for pci.

Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>