Enable Fastboot for ubuntu images

Fastboot is useful on non-Android images for:
  -- flashing bootloader and trustzone components, and
  -- fastboot boot to boot new kernels.

So check that partitions exist (for flash and erase) at erase or flash times,
not when starting the usb listener.

Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>
fw_printenv/fw_setenv fix for mmc.
ARMv7: start.S: stay in HYP mode if u-boot is entered in it

The KVM and Xen hypervisors for the Cortex-A15 virtualization
implementation need to be entered in HYP mode. Should the primary
board firmware already enter HYP mode (Calxeda firmware does that),
we should not deliberately drop back to SVC mode.
Since U-boot does not use the MMU, running in HYP mode is just fine.

Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
smdk5410: Remove switch from NS HYP to NS SVC to allow booting in HYP mode.
ARMv7: Add support for HYP mode to exception handlers.
ARMv7: Fix invalid memory access bug in swi interrupt handler
Exynos 5422: stay in HYP mode

If BL1 and 2 leave the bootloader in HYP mode, stay there.  This enables KVM
in booted linux.

Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>