Merged in masayuki2009/nuttx.nuttx/lc823450_http_streaming (pull request #560)

lc823450 http streaming

* arch/arm/src/lc823450: Use spinlock APIs in lc823450_gpio.c

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

* arch/arm/src/lc823450: Add a warning message in up_ack_irq()

    In SMP mode, H/W interrupts should be handled on CPU0 to avoid deadlocks.

    Other changes:
    Fix a potential race condition in up_enable_irq()
    Use spinlock APIs instead of critical section APIs.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

* arch/arm/src/lc823450: Enable HRT_TIMER in lc823450_timerisr.c

    Other changes:
    Fix style violations and call up_enable_irq() to assign CPU0 for IRQ handling.
    Use spinlock APIs instead of critical section APIs.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

* arch/arm/src/lc823450: Fix race conditions in dma/usbdev.

    In SMP mode, critical data must be protected explicitly.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

* configs/lc823450-xgevk: Update README.txt

    Add notes on .gdbinit and networking. Update comments on SMP.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

* configs/lc823450-xgevk: Update defconfigs

    Enable HRT_TIMER, LC823450_MTM0_TICK, SPINLOCK_IRQ
    Enable NET_TCP_RWND_CONTROL, NXPLAYER_HTTP_STREAMING_SUPPORT (rndis only)

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

Approved-by: Gregory Nutt <gnutt@nuttx.org>