clk: qcom: Add support for controlling Fabia PLL

Fabia PLL is a Digital Frequency Locked Loop (DFLL) clock
generator which has a wide range of frequency output. It
supports dynamic updating of the output frequency
("frequency slewing") without need to turn off the PLL
before configuration. Add support for initial configuration
and programming sequence to control fabia PLLs.

Signed-off-by: Amit Nischal <anischal@codeaurora.org>
[sboyd: Shorten code a little]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>