clk: qcom: smd: Update MSM8976 RPM clocks.

MSM8976 does not have rpm clock named mmssnoc,
instead it's called sysmmnoc, drop define and reuse.
While we are at it add XO clock to list.

Fixes: 7d61e773 ("clk: qcom: smd: Add support for MSM8976 rpm clocks")
Signed-off-by: Adam Skladowski <a39.skl@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220426090226.27293-1-a39.skl@gmail.com