drm/amdgpu: Refine Cleaner Shader MEC firmware version for GFX10.1.x GPUs

Update the minimum firmware version for the Cleaner Shader in the
gfx_v10_0_sw_init function.

This change adjusts the minimum required firmware version for the MEC
firmware from 152 to 151, allowing for broader compatibility with
GFX10.1 GPUs.

Fixes: 25961bad ("drm/amdgpu/gfx10: Add cleaner shader for GFX10.1.10")
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>