Kconfig: Move config SYS_MALLOC_LEN to Kconfig for zynq

This patch moves the the config SYS_MALLOC_LEN to
Kconfig. It will be just for Zynq arch and to do
will be for all other archs.

Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Vipul Kumar <vipul.kumar@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/zynq_cse_qspi_defconfig b/configs/zynq_cse_qspi_defconfig
index 0b2cd8c..c27daad 100644
--- a/configs/zynq_cse_qspi_defconfig
+++ b/configs/zynq_cse_qspi_defconfig
@@ -8,6 +8,7 @@
 CONFIG_DEBUG_UART_CLOCK=0
 CONFIG_SPL_STACK_R_ADDR=0x200000
 # CONFIG_ZYNQ_DDRC_INIT is not set
+CONFIG_SYS_MALLOC_LEN=0x1000
 # CONFIG_CMD_ZYNQ is not set
 CONFIG_DEFAULT_DEVICE_TREE="zynq-cse-qspi-single"
 CONFIG_DEBUG_UART=y