clk: qoriq: add clock configuration for ls1088a soc

Clock on ls1088a chip takes primary clocking input from the external
SYSCLK signal. The SYSCLK input (frequency) is multiplied using
multiple phase locked loops (PLL) to create a variety of frequencies
which can then be passed to a variety of internal logic, including
cores and peripheral IP modules.

Signed-off-by: Tang Yuantian <andy.tang@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>