[ARM] pxa: add basic support for HP iPAQ h5000

This patch adds HP iPAQ h5000's (h5400, h5500) basic definitions.

Kernel will able to boot, work via serial console, mount filesystems
placed on flashes and run USB gadgets (g_ether by default).

Other device drivers (frame buffer, LCD, touchscreen, backlight,
bluetooth, w1/battery, ...) are depend on SAMCOP and MediaQ
SoCs/MFDs, drivers to which will be submitted too, after massive
cleanups.

This machine will be used as "real user" for these new drivers.

This is an updated version of the patch, which contains fixes proposed on
linux-arm-kernel mailing list.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Milan Plzik <milan.plzik@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>