SH4: Switch serial emulation to qemu_irq

SH4: Switch serial emulation to qemu_irq

This patches makes SH serial emulation use qemu_irq in its interface.

        * hw/sh.h (sh_serial_init): Take qemu_irq, not intc_source.
        * hw/sh7750.c (sh7750_init): Adjust.
        * hw/sh_intc.c (sh_intc_set_irq): Don't assert or deassert
        irq more than once.
        * hw/sh_serial.c (sh_serial_state): Use qemu_irq, not intc_source.
        (sh_serial_clear_fifo, sh_serial_ioport_write)
        (sh_serial_receive_byte): Adjust.
        (sh_serial_init): Take qemu_irq, not intc_source.

(Vladimir Prus)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5769 c046a42c-6fe2-441c-8c8c-71466251a162