misc: move FLASH_MINOR into miscdevice.h and fix conflicts

FLASH_MINOR is used in both drivers/char/nwflash.c and
drivers/sbus/char/flash.c with conflict minor numbers.

Move all the definitions of FLASH_MINOR into miscdevice.h.
Rename FLASH_MINOR for drivers/char/nwflash.c to NWFLASH_MINOR
and FLASH_MINOR for drivers/sbus/char/flash.c to SBUS_FLASH_MINOR.

Link: https://lore.kernel.org/lkml/[e-mail]/t/
Suggested-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Zhenzhong Duan <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

arch/arm/include/asm/nwflash.h

···
 #ifndef _FLASH_H
 #define _FLASH_H
 
-#define FLASH_MINOR		 160	/* MAJOR is 10 - miscdevice */
 #define CMD_WRITE_DISABLE	 0
 #define CMD_WRITE_ENABLE	 0x28
 #define CMD_WRITE_BASE64K_ENABLE 0x47

drivers/char/nwflash.c

···
 
 static struct miscdevice flash_miscdev =
 {
-	FLASH_MINOR,
+	NWFLASH_MINOR,
 	"nwflash",
 	&flash_fops
 };

drivers/sbus/char/flash.c

···
 	unsigned long busy;		/* In use? */
 } flash;
 
-#define FLASH_MINOR	152
-
 static int
 flash_mmap(struct file *file, struct vm_area_struct *vma)
 {
···
 	.release =	flash_release,
 };
 
-static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
+static struct miscdevice flash_dev = { SBUS_FLASH_MINOR, "flash", &flash_fops };
 
 static int flash_probe(struct platform_device *op)
 {

include/linux/miscdevice.h

···
 #define SUN_OPENPROM_MINOR	139
 #define DMAPI_MINOR		140	/* unused */
 #define NVRAM_MINOR		144
+#define SBUS_FLASH_MINOR	152
 #define SGI_MMTIMER		153
 #define PMU_MINOR		154
 #define STORE_QUEUE_MINOR	155	/* unused */
 #define LCD_MINOR		156
 #define AC_MINOR		157
 #define BUTTON_MINOR		158	/* Major 10, Minor 158, /dev/nwbutton */
+#define NWFLASH_MINOR		160	/* MAJOR is 10 - miscdevice */
 #define ENVCTRL_MINOR		162
 #define I2O_MINOR		166
 #define UCTRL_MINOR		174