ehci-mx5/6: Make board_ehci_hcd_init() optional

A custom board_ehci_hcd_init() may be unneeded, so add a weak default
implementation doing nothing.

By the way, use simple __weak from linux/compiler.h for
board_ehci_hcd_postinit() instead of weak alias with full attribute.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>

drivers/usb/host/ehci-mx5.c

@@ -290,12 +290,14 @@ int mxc_set_usbcontrol(int port, unsigned int flags)
 	return ret;
 }
 
-void __board_ehci_hcd_postinit(struct usb_ehci *ehci, int port)
+int __weak board_ehci_hcd_init(int port)
 {
+	return 0;
 }
 
-void board_ehci_hcd_postinit(struct usb_ehci *ehci, int port)
-	__attribute((weak, alias("__board_ehci_hcd_postinit")));
+void __weak board_ehci_hcd_postinit(struct usb_ehci *ehci, int port)
+{
+}
 
 int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
 {

drivers/usb/host/ehci-mx6.c

@@ -159,6 +159,11 @@ static void usbh1_oc_config(void)
 	__raw_writel(val, usbother_base + USB_H1_CTRL_OFFSET);
 }
 
+int __weak board_ehci_hcd_init(int port)
+{
+	return 0;
+}
+
 int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
 {
 	struct usb_ehci *ehci;