drivers/usb/ehci_debug: Add x86_64 support

Use proper int to pointer conversions.

Tested on Lenovo T410 with x86_64 enabled. Still works.

Change-Id: I4ed62297fb47d7d83d4b28e80f3770de99ce70f7
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37393
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/usb/pci_ehci.c b/src/drivers/usb/pci_ehci.c
index a740d50..dfc78cc 100644
--- a/src/drivers/usb/pci_ehci.c
+++ b/src/drivers/usb/pci_ehci.c
@@ -116,6 +116,7 @@
 
 u8 *pci_ehci_base_regs(pci_devfn_t sdev)
 {
-	u8 *base = (u8 *)(pci_s_read_config32(sdev, EHCI_BAR_INDEX) & ~0x0f);
+	u32 bar = pci_s_read_config32(sdev, EHCI_BAR_INDEX) & ~0x0f;
+	u8 *base = (u8 *)(uintptr_t)bar;
 	return base + HC_LENGTH(read32(base));
 }