[PATCH 3/4] mips: zboot: Fix "no previous prototype" build warning

[Serge Semin <fancer.lancer@gmail.com>]

Without having the putc() prototype forwardly declared the next
build-warning is printed:

arch/mips/boot/compressed/uart-prom.c:6:6: warning: no previous prototype for ‘putc’ [-Wmissing-prototypes]
...

Fix that by adding the "decompress.h" header file with the putc() function
declaration to the source files which have the method redefined.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
 arch/mips/boot/compressed/uart-16550.c   | 2 ++
 arch/mips/boot/compressed/uart-alchemy.c | 2 ++
 arch/mips/boot/compressed/uart-prom.c    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/mips/boot/compressed/uart-16550.c b/arch/mips/boot/compressed/uart-16550.c
index 09dcd2c561d9..db618e72a0c4 100644
--- a/arch/mips/boot/compressed/uart-16550.c
+++ b/arch/mips/boot/compressed/uart-16550.c
@@ -8,6 +8,8 @@
 
 #include <asm/addrspace.h>
 
+#include "decompress.h"
+
 #if defined(CONFIG_MACH_LOONGSON64) || defined(CONFIG_MIPS_MALTA)
 #define UART_BASE 0x1fd003f8
 #define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
diff --git a/arch/mips/boot/compressed/uart-alchemy.c b/arch/mips/boot/compressed/uart-alchemy.c
index 8ec63011e7dc..003967c084b3 100644
--- a/arch/mips/boot/compressed/uart-alchemy.c
+++ b/arch/mips/boot/compressed/uart-alchemy.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <asm/mach-au1x00/au1000.h>
 
+#include "decompress.h"
+
 void putc(char c)
 {
 	alchemy_uart_putchar(AU1000_UART0_PHYS_ADDR, c);
diff --git a/arch/mips/boot/compressed/uart-prom.c b/arch/mips/boot/compressed/uart-prom.c
index a8a0a32e05d1..5fa3b9945333 100644
--- a/arch/mips/boot/compressed/uart-prom.c
+++ b/arch/mips/boot/compressed/uart-prom.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <asm/setup.h>
 
+#include "decompress.h"
+
 void putc(char c)
 {
 	prom_putchar(c);
-- 
2.43.0