arm: remove duplicated prototypes in u-boot.arm.h

Remove the function prototypes duplicated between u-boot.arm.h
and init.h/common.h

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

arch/arm/include/asm/u-boot-arm.h

@@ -24,16 +24,13 @@ extern ulong _datarelro_start_ofs;
 extern ulong IRQ_STACK_START_IN;	/* 8 bytes in IRQ stack */
 
 /* cpu/.../cpu.c */
-int	cpu_init(void);
 int	cleanup_before_linux(void);
 
 /* Set up ARMv7 MMU, caches and TLBs */
 void	cpu_init_cp15(void);
 
 /* cpu/.../arch/cpu.c */
-int	arch_cpu_init(void);
 int	arch_misc_init(void);
-int	arch_early_init_r(void);
 
 /* board/.../... */
 int	board_init(void);