Step to move shared irq handling out of core in the long run. So, use
irq_proxy implementation from base in os and implement shared irq handling
in platform driver of x86 (pci_drv).
Fixes#1471
Drivers like SD-Card, platform, AHCI, and framebuffer are specified as Exynos5
compliant. But they are at least not compliant with Odroid-XU although this is
Exynos5. Thus, prevent tests that rely on such drivers when building for
hw_odoid_xu. Furthermore, make previous Arndale regulator/consts.h,
uart_defs.h, and some Board_base enums available to all Exynos5 builds to
enable at least building the drivers.
Fixes#1419
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
