configs: Migrate CONFIG_SYS_LDSCRIPT to Kconfig

In order to migrate this symbol to Kconfig introduce a new symbol to
guard it, CONFIG_SYS_CUSTOM_LDSCRIPT.  When that is set we can then
provide the exact final location o the script.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/zynq_cse_nand_defconfig b/configs/zynq_cse_nand_defconfig
index 62ed8f73..fca0382 100644
--- a/configs/zynq_cse_nand_defconfig
+++ b/configs/zynq_cse_nand_defconfig
@@ -8,6 +8,8 @@
 CONFIG_SPL_STACK_R_ADDR=0x200000
 CONFIG_SPL=y
 CONFIG_SYS_MALLOC_LEN=0x1000
+CONFIG_SYS_CUSTOM_LDSCRIPT=y
+CONFIG_SYS_LDSCRIPT="arch/arm/mach-zynq/u-boot.lds"
 # CONFIG_BOARD_LATE_INIT is not set
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_SPL_STACK_R=y