rpi4: add a mapping for the PCIe XHCI controller MMIO registers (ARM 32bit)

Create a non-cacheable mapping for the 0x600000000 physical memory region,
where MMIO registers for the PCIe XHCI controller are instantiated by the
PCIe bridge. Due to 32bit limit in the CPU virtual address space in ARM
32bit mode, this region is mapped at 0xff800000 CPU virtual address.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
diff --git a/arch/arm/mach-bcm283x/Kconfig b/arch/arm/mach-bcm283x/Kconfig
index e6eb904..b3287ce 100644
--- a/arch/arm/mach-bcm283x/Kconfig
+++ b/arch/arm/mach-bcm283x/Kconfig
@@ -36,6 +36,7 @@
 	select BCM2711
 	select ARMV7_LPAE
 	select CPU_V7A
+	select PHYS_64BIT
 
 config BCM2711_64B
 	bool "Broadcom BCM2711 SoC 64-bit support"