remoteproc: zynqmp: fix lockstep mode memory region

In lockstep mode, r5 core0 uses TCM of R5 core1. Following is lockstep
mode memory region as per hardware reference manual.

    |      *TCM*         |   *R5 View* | *Linux view* |
    | R5_0 ATCM (128 KB) | 0x0000_0000 | 0xFFE0_0000  |
    | R5_0 BTCM (128 KB) | 0x0002_0000 | 0xFFE2_0000  |

However, driver shouldn't model it as above because R5 core0 TCM and core1
TCM has different power-domains mapped to it.
Hence, TCM address space in lockstep mode should be modeled as 64KB
regions only where each region has its own power-domain as following:

    |      *TCM*         |   *R5 View* | *Linux view* |
    | R5_0 ATCM0 (64 KB) | 0x0000_0000 | 0xFFE0_0000  |
    | R5_0 BTCM0 (64 KB) | 0x0002_0000 | 0xFFE2_0000  |
    | R5_0 ATCM1 (64 KB) | 0x0001_0000 | 0xFFE1_0000  |
    | R5_0 BTCM1 (64 KB) | 0x0003_0000 | 0xFFE3_0000  |

This makes driver maintanance easy and makes design robust for future
platorms as well.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Link: https://lore.kernel.org/r/20240412183708.4036007-2-tanmay.shah@amd.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>