sunxi: move #ifdef guards around tzpc_init() to header file

Some later 32-bit SoCs require some setup of the Secure Peripherals
Controller, which is handled in tzpc_init().
At the moment this is guarded in board.c by some #ifdefs selecting the
SoCs that need it.

Move those #ifdef guards into the header file, providing an empty stub
function for all other SoCs, so that the #ifdefs can be removed from the
.c file, to improve readability.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

arch/arm/include/asm/arch-sunxi/tzpc.h

@@ -28,6 +28,12 @@ struct sunxi_tzpc {
 #define SUN8I_H3_TZPC_DECPORT1_ALL  0xff
 #define SUN8I_H3_TZPC_DECPORT2_ALL  0x7f
 
+#if defined CONFIG_MACH_SUN6I || defined CONFIG_MACH_SUN8I_H3
 void tzpc_init(void);
+#else
+static inline void tzpc_init(void)
+{
+}
+#endif
 
 #endif /* _SUNXI_TZPC_H */

arch/arm/mach-sunxi/board.c

@@ -458,10 +458,8 @@ void board_init_f(ulong dummy)
 {
 	sunxi_sram_init();
 
-#if defined CONFIG_MACH_SUN6I || defined CONFIG_MACH_SUN8I_H3
 	/* Enable non-secure access to some peripherals */
 	tzpc_init();
-#endif
 
 	clock_init();
 	timer_init();