ARM: zynq: Move CONFIG_SYS_TEXT_BASE to Kconfig

Enable CONFIG_SYS_TEXT_BASE via Kconfig.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_picozed_defconfig b/configs/zynq_picozed_defconfig
index d8c76a7..529a9ad 100644
--- a/configs/zynq_picozed_defconfig
+++ b/configs/zynq_picozed_defconfig
@@ -1,5 +1,6 @@
 CONFIG_ARM=y
 CONFIG_ARCH_ZYNQ=y
+CONFIG_SYS_TEXT_BASE=0x4000000
 CONFIG_DEFAULT_DEVICE_TREE="zynq-picozed"
 CONFIG_SYS_NO_FLASH=y
 # CONFIG_DISPLAY_CPUINFO is not set