arm: qemu: fix failure in flash initialization if booting from TF-A

If U-Boot is loaded and started from TF-A (you need to change
SYS_TEXT_BASE to 0x60000000), it will hang up at flash initialization.

If secure mode is off (default, or -machine virt,secure=off) at qemu,
it will provide dtb with two flash memory banks:
	flash@0 {
		bank-width = <0x4>;
		reg = <0x0 0x0 0x0 0x4000000 0x0 0x4000000 0x0 0x4000000>;
		compatible = "cfi-flash";
	};
If secure mode is on, on the other hand, qemu provides dtb with 1 bank:
	flash@0 {
		bank-width = <0x4>;
		reg = <0x0 0x4000000 0x0 0x4000000>;
		compatible = "cfi-flash";
	};

As a result, flash_init()/flash_get_size() will eventually fail.
With this patch applied, relevant CONFIG values are modified.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

arch/arm/Kconfig

@@ -840,6 +840,7 @@ config ARCH_OWL
 
 config ARCH_QEMU
 	bool "QEMU Virtual Platform"
+	select ARCH_SUPPORT_TFABOOT
 	select DM
 	select DM_SERIAL
 	select OF_CONTROL

include/configs/qemu-arm.h

@@ -46,8 +46,13 @@
 #define CONFIG_SYS_CBSIZE 512
 
 #define CONFIG_SYS_MONITOR_BASE		CONFIG_SYS_TEXT_BASE
+#ifdef CONFIG_TFABOOT
+#define CONFIG_SYS_FLASH_BASE		0x4000000
+#define CONFIG_SYS_MAX_FLASH_BANKS	1
+#else
 #define CONFIG_SYS_FLASH_BASE		0x0
 #define CONFIG_SYS_MAX_FLASH_BANKS	2
+#endif
 #define CONFIG_SYS_MAX_FLASH_SECT	256 /* Sector: 256K, Bank: 64M */
 
 #endif /* __CONFIG_H */