drm/amd/amdgpu: Fix errors & warnings in amdgpu _bios, _cs, _dma_buf, _fence.c

The following checkpatch errors & warning is removed.

ERROR: else should follow close brace '}'
ERROR: trailing statements should be on next line
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
WARNING: Possible repeated word: 'Fences'
WARNING: Missing a blank line after declarations
WARNING: braces {} are not necessary for single statement blocks
WARNING: Comparisons should place the constant on the right side of the test
WARNING: printk() should include KERN_<LEVEL> facility level

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>