ARM: berlin: dts: add CLKID_CPU for BG2Q

Marvell Berlin BG2Q SoC also has a clock for the CPU, add a
corresponding CLKID to the dt-binding include.
Signed-off-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

include/dt-bindings/clock/berlin2q.h

@@ -29,3 +29,4 @@
 #define CLKID_SMEMC		24
 #define CLKID_PCIE		25
 #define CLKID_TWD		26
+#define CLKID_CPU		27