msm: gemini: Rename ijpeg clocks to match MSM naming convention

For consistency, a core clocks main clock should be called "core_clk",
its register interface clock "iface_clk" and its memory clock
"mem_clk". Rename msm_gemini's ijpeg clocks to match this convention.

Change-Id: Icae549c1e49e7f3ad13b63e71a8f688f64bc871a
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>