clk: msm: clock-gcc: Fix sibling for mdp and jpeg0 clock

The clocks of mdp and jpeg branch clock set rates would fail in case the
sibling is set. Also fix the blsp2_uart div values and the external parent
for byte clock.

Change-Id: I65ccc0dc9d941562b8f65a263d2e40e7fceb41c1
Signed-off-by: Taniya Das <tdas@codeaurora.org>