usb: ehci-generic: support reset control for generic EHCI

This driver is designed in a generic manner, so resets should be
handled generically as well.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/usb/host/ehci-generic.c b/drivers/usb/host/ehci-generic.c
index 6291ed2..2190adb 100644
--- a/drivers/usb/host/ehci-generic.c
+++ b/drivers/usb/host/ehci-generic.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <clk.h>
+#include <reset.h>
 #include <asm/io.h>
 #include <dm.h>
 #include "ehci.h"
@@ -37,6 +38,18 @@
 		clk_free(&clk);
 	}
 
+	for (i = 0; ; i++) {
+		struct reset_ctl reset;
+		int ret;
+
+		ret = reset_get_by_index(dev, i, &reset);
+		if (ret < 0)
+			break;
+		if (reset_deassert(&reset))
+			printf("failed to deassert reset %d\n", i);
+		reset_free(&reset);
+	}
+
 	hccr = map_physmem(dev_get_addr(dev), 0x100, MAP_NOCACHE);
 	hcor = (struct ehci_hcor *)((uintptr_t)hccr +
 				    HC_LENGTH(ehci_readl(&hccr->cr_capbase)));