rockchip: rv1108: use correct API for board callback

Use board_early_init_f() instead of mach_cpu_init() for board, the
board_early_init_f() is used for board init and after dm_initf, while
the mach_cpu_init() is used for CPU/SOC and before dm_initf()(not able
to use syscon API).

Fixes: 9cec336708 ("rockchip: evb-rv1108: Use syscon API to get grf base")
Fixes: 4aa33690fc {"rockchip: elgin-rv1108: Use syscon API to get grf base")

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>

board/elgin/elgin_rv1108/elgin_rv1108.c

@@ -15,7 +15,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-int mach_cpu_init(void)
+int board_early_init_f(void)
 {
 	struct rv1108_grf *grf;
 	enum {

board/rockchip/evb_rv1108/evb_rv1108.c

@@ -14,7 +14,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-int mach_cpu_init(void)
+int board_early_init_f(void)
 {
 	struct rv1108_grf *grf;
 	enum {