usb: ehci: Fix accessors for big-endian platforms and descriptors

Commit 9000eddbae ("drivers/usb/ehci: Use platform-specific accessors")
broke USB 2.0 on big-endian platforms because for them writel/readl()
does automatic conversion of BE data to LE.

Proper implementation requires to use "raw" variant of these accessors
which read/write data without messing with endianess.

While at it replace cpu_to_be32() to be32_to_cpu() in readl() to
keep sane semantics.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Marek Vasut <marex@denx.de>
Reported-by: Vladimir Boroda <boroda@yahoo.com>

drivers/usb/host/ehci.h

@@ -101,11 +101,11 @@ struct usb_linux_config_descriptor {
 } __attribute__ ((packed));
 
 #if defined CONFIG_EHCI_DESC_BIG_ENDIAN
-#define ehci_readl(x)		cpu_to_be32(readl(x))
-#define ehci_writel(a, b)	writel(cpu_to_be32(b), a)
+#define ehci_readl(x)		be32_to_cpu(__raw_readl(x))
+#define ehci_writel(a, b)	__raw_writel(cpu_to_be32(b), a)
 #else
-#define ehci_readl(x)		cpu_to_le32(readl(x))
-#define ehci_writel(a, b)	writel(cpu_to_le32(b), a)
+#define ehci_readl(x)		readl(x)
+#define ehci_writel(a, b)	writel(b, a)
 #endif
 
 #if defined CONFIG_EHCI_MMIO_BIG_ENDIAN