msm: clock: Fix measurement debugfs node creation

A recent change introduced a bug that caused clk_get to be called
on the 'measure' clock even before the measure clock had been
registered. Fix this by calling clock_debug_init() after registering
the first clock table, at the end of msm_clock_init().

Change-Id: I4b506fe55e0269d0f1229a9836058a6ffb79a520
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>