configs: am62x_evm_r5: Increase size of malloc_simple heap after relocation

On AM62x SK we can see a boot failure with signature "alloc space
exhausted", so fix by increasing size of SPL_STACK_R_MALLOC_SIMPLE_LEN.

Fixes: 128f8129 ("arm: dts: k3: binman: am625: add support for signing TIFSSTUB Images")
Signed-off-by: Judith Mendez <jm@ti.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Bryan Brattlof <bb@ti.com>

configs/am62x_evm_r5_defconfig

@@ -26,6 +26,7 @@ CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
 CONFIG_SPL_BSS_START_ADDR=0x43c3b000
 CONFIG_SPL_BSS_MAX_SIZE=0x3000
 CONFIG_SPL_STACK_R=y
+CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x200000
 CONFIG_SPL_SIZE_LIMIT=0x3A7F0
 CONFIG_SPL_SIZE_LIMIT_PROVIDE_STACK=0x3500
 CONFIG_SPL_FS_FAT=y