ata: Make pata_of_platform.c compile again and work on non-PPC platforms

This patch adds missing #includes, makes the driver selectable on
non-PPC OF-enabled platforms and fixes property value accesses to
be correct in Little Endian system.

Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 5987e0b..c6ef9d0 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -820,7 +820,7 @@
 
 config PATA_OF_PLATFORM
 	tristate "OpenFirmware platform device PATA support"
-	depends on PATA_PLATFORM && PPC_OF
+	depends on PATA_PLATFORM && OF
 	help
 	  This option enables support for generic directly connected ATA
 	  devices commonly found on embedded systems with OpenFirmware