lib: sbi: Add console_puts() callback in the console device

We add console_puts() callback in the console device which allows
console drivers (such as semihosting) to implement a specialized
way to output character string.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

include/sbi/sbi_console.h

@@ -19,6 +19,9 @@ struct sbi_console_device {
 	/** Write a character to the console output */
 	void (*console_putc)(char ch);
 
+	/** Write a character string to the console output */
+	unsigned long (*console_puts)(const char *str, unsigned long len);
+
 	/** Read a character from the console input */
 	int (*console_getc)(void);
 };