ARM: remove CONFIG_ARM920T defines

CONFIG_CPU_ARM920T was introduced into Kconfig by commit 2e07c249a67e
(kconfig: arm: introduce symbol for ARM CPUs).

This commit removes all the defines of CONFIG_ARM920T and replaces the
only reference in drivers/usb/host/ohci-hcd.c with CONFIG_CPU_ARM920T.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index dc0a4e3..2ab28a4 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -47,7 +47,7 @@
 #include <asm/arch/hardware.h>	/* needed for AT91_USB_HOST_BASE */
 #endif
 
-#if defined(CONFIG_ARM920T) || \
+#if defined(CONFIG_CPU_ARM920T) || \
     defined(CONFIG_S3C24X0) || \
     defined(CONFIG_440EP) || \
     defined(CONFIG_PCI_OHCI) || \