The vzalloc(size) is equivalent to kzalloc(size, 0).  Move it to
include/linux/compat.h as an inline function in order to avoid the
function call overhead.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>

- move linux specific defines from usb and video code
  into linux/compat.h
- move common linux specific defines from include/ubi_uboot.h
  to linux/compat.h
- add for new mtd/ubi/ubifs sync new needed linux specific
  defines to linux/compat.h

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
[trini: Add spin_lock_irqsave/spin_unlock_irqrestore dummies from
usb/lin_gadet_compat.h]
Signed-off-by: Tom Rini <trini@ti.com>