m68k: coldfire: fix warnings in uboot argument processing

When building with W=1:

      CC      arch/m68k/kernel/uboot.o
    arch/m68k/kernel/uboot.c: In function ‘parse_uboot_commandline’:
    arch/m68k/kernel/uboot.c:68:36: warning: variable ‘uboot_initrd_end’ set but not used [-Wunused-but-set-variable]
      unsigned long uboot_initrd_start, uboot_initrd_end;
                                        ^~~~~~~~~~~~~~~~
    arch/m68k/kernel/uboot.c:68:16: warning: variable ‘uboot_initrd_start’ set but not used [-Wunused-but-set-variable]
      unsigned long uboot_initrd_start, uboot_initrd_end;
                    ^~~~~~~~~~~~~~~~~~
    arch/m68k/kernel/uboot.c:66:16: warning: variable ‘uboot_kbd’ set but not used [-Wunused-but-set-variable]
      unsigned long uboot_kbd;
                    ^~~~~~~~~
    arch/m68k/kernel/uboot.c: At top level:
    arch/m68k/kernel/uboot.c:90:13: warning: no previous prototype for ‘process_uboot_commandline’ [-Wmissing-prototypes]
     __init void process_uboot_commandline(char *commandp, int size)
                 ^~~~~~~~~~~~~~~~~~~~~~~~~

A couple of issues here. Firstly we already have a bootinfo.h that has a
prototype for process_uboot_commandline(), we should include that.
Secondly uboot_kbd is not used at all and can be removed. Thirdly the
conditional code based on CONFIG_BLK_DEV_INITRD means that sometimes
uboot_initrd_start and uboot_initrd_end are not needed. Make their
declaration and asignment conditional on CONFIG_BLK_DEV_INITRD same as
the code that uses them.
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

arch/m68k/kernel/uboot.c

@@ -27,6 +27,7 @@
 #include <asm/irq.h>
 #include <asm/machdep.h>
 #include <asm/sections.h>
+#include <asm/bootinfo.h>
 
 /*
  * parse_uboot_commandline
@@ -63,20 +64,22 @@ static void __init parse_uboot_commandline(char *commandp, int size)
 {
 	extern unsigned long _init_sp;
 	unsigned long *sp;
-	unsigned long uboot_kbd;
-	unsigned long uboot_initrd_start, uboot_initrd_end;
 	unsigned long uboot_cmd_start, uboot_cmd_end;
+#if defined(CONFIG_BLK_DEV_INITRD)
+	unsigned long uboot_initrd_start, uboot_initrd_end;
+#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
 
 	sp = (unsigned long *)_init_sp;
-	uboot_kbd = sp[1];
-	uboot_initrd_start = sp[2];
-	uboot_initrd_end = sp[3];
 	uboot_cmd_start = sp[4];
 	uboot_cmd_end = sp[5];
 
 	if (uboot_cmd_start && uboot_cmd_end)
 		strncpy(commandp, (const char *)uboot_cmd_start, size);
+
 #if defined(CONFIG_BLK_DEV_INITRD)
+	uboot_initrd_start = sp[2];
+	uboot_initrd_end = sp[3];
+
 	if (uboot_initrd_start && uboot_initrd_end &&
 	    (uboot_initrd_end > uboot_initrd_start)) {
 		initrd_start = uboot_initrd_start;