configs: add falcon mode fragment for k3 devices

configs: add falcon mode fragment for k3 devices

This fragment enables falcon mode for K3 platforms and modifies the
memory map.

To have enough stack and heap space for loading kernel image as
FIT the memory map was modified by expanding stack + heap size, the
PRELOADED_BL33_BASE in TFA has to also be updated to 0x82000000 since
the kernel needs to be loaded at 2MiB aligned address along with
updating K3_HW_CONFIG_BASE to 0x88000000 for the DT passed to kernel.

Modified memory map for R5 SPL (modified addresses marked with *):

0x80000000 +-------------------------------+ Start of DDR
  512KiB   |   TFA reserved memory space   | CONFIG_K3_ATF_LOAD_ADDR*
0x80080000 +-------------------------------+
 31.5MiB   |            Unused             |
0x82000000 +-------------------------------+ PRELOADED_BL33_BASE* in TFA
           |                               | CONFIG_SYS_LOAD_ADDR*
   57MiB   |   Kernel + initramfs Image    | CONFIG_SPL_LOAD_FIT_ADDRESS*
           |                               |
0x85900000 +-------------------------------+
           |                               |
           |  R5 U-Boot SPL Stack + Heap   |
   39MiB   |       (size defined by        |
           |SPL_STACK_R_MALLOC_SIMPLE_LEN*)|
           |                               |
0x88000000 +-------------------------------+ CONFIG_SPL_STACK_R_ADDR*
           |                               | K3_HW_CONFIG_BASE* in TFA
   16MiB   |          Kernel DTB           | CONFIG_SPL_PAYLOAD_ARGS_ADDR*
           |                               |
0x89000000 +-------------------------------+
  331MiB   | Device Manager (DM) Load Addr |
0x9db00000 +-------------------------------+
   12MiB   |          DM Reserved          |
0x9e700000 +-------------------------------+
    1MiB   |            Unused             |
0x9e800000 +-------------------------------+ BL32_BASE in TFA
   24MiB   |             OPTEE             |
0xa0000000 +-------------------------------+ End of DDR (512MiB)

Signed-off-by: Anshul Dalal <anshuld@ti.com>