keyboard: Do not include <linux/irq.>

The top of <linux/irq.h> has this comment:

 * Please do not include this file in generic code.  There is currently
 * no requirement for any architecture to implement anything held
 * within this file.
 *
 * Thanks. --rmk

Remove inclusion of <linux/irq.>, to prevent the following compile error
from happening soon:

| include/linux/irq.h:132: error: redefinition of ‘struct irq_data’
| include/linux/irq.h:286: error: redefinition of ‘struct irq_chip’

drivers/tty/vt/keyboard.c needs to include <asm/irq_regs.h> for get_irq_regs():

| drivers/tty/vt/keyboard.c:497: error: implicit declaration of function ‘get_irq_regs’
| drivers/tty/vt/keyboard.c:497: warning: initialization makes pointer from integer without a cast

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>