drm/amdgpu: fix for coding style issues

Fixed below checkpatch warnings and errors

drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:131: CHECK: Comparison to NULL could be written "apd"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:150: CHECK: Comparison to NULL could be written "apd"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:196: CHECK: Prefer kernel type 'u64' over 'uint64_t'
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:224: CHECK: Please don't use multiple blank lines
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:226: CHECK: Comparison to NULL could be written "!adev->acp.acp_genpd"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:233: CHECK: Please don't use multiple blank lines
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:239: CHECK: Alignment should match open parenthesis
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:241: CHECK: Comparison to NULL could be written "!adev->acp.acp_cell"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:247: CHECK: Comparison to NULL could be written "!adev->acp.acp_res"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:253: CHECK: Comparison to NULL could be written "!i2s_pdata"
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:350: CHECK: Alignment should match open parenthesis
drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c:550: ERROR: that open brace { should be on the previous line

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>