clk:spear1340:Fix: Rename clk ids within predefined limit

The max limit of con_id is 16 and dev_id is 20. As of now for spear1340, many
clk ids are exceeding this predefined limit.

This patch rename clk ids like:
    mux_clk -> _mclk
    gate_clk -> _gclk
    synth_clk -> syn_clk
    gmac_phy -> phy_
    gmii_125m_pad_ -> gmii_pad

Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>