dt-bindings: marvell,mmp2: Add clock id for the LCDC clock

The peripheral clock is required for access the the LCDC registers. It
is in fact separate from the "AXI clock" that is optionally used to
generate the pixel clock and as such requires a separate clock id.

Link: https://lists.freedesktop.org/archives/dri-devel/2019-January/203975.htmlSigned-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

include/dt-bindings/clock/marvell,mmp2.h

@@ -71,6 +71,7 @@
 #define MMP2_CLK_CCIC1_MIX		117
 #define MMP2_CLK_CCIC1_PHY		118
 #define MMP2_CLK_CCIC1_SPHY		119
+#define MMP2_CLK_DISP0_LCDC		120
 
 #define MMP2_NR_CLKS			200
 #endif