The function stm32_i2c_get_setup_from_fdt() was using fdt_getprop() to
to get some i2c node properties, and set a default value if the node
was not found. The function fdt_read_uint32_default() already does
this in a simpler way.
Remove useless STM32_I2C_SPEED_DEFAULT.
Change-Id: I74c6295bb5765ee7c7e0a9ae020b741f1fe022a6
Signed-off-by: Yann Gautier <yann.gautier@st.com>