clk: qcom: Fix compile warnings

Fix the following compiler warning(s) from gcc 6.1.1 with -Werror enabled:

 drivers/clk/qcom/mdss/mdss-pll.c:220:
   format '%d' expects a matching 'int' argument [-Werror=format=]
   pr_info("%d: MDSS pll label not specified\n");

Fixes: 0fd7ae3f ("clk:qcom: add mdss dsi and dp pll driver support")
Change-Id: Ic0dedbadb3533695fc7166c172946607e8ccb21f
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>