drm/amdgpu: Mark 'kgd_gfx_aldebaran_clear_address_watch' & 'kgd_gfx_v11_clear_address_watch' functions as static

Below two functions cause a warning because they lack a prototype:

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c:164:10: warning: no previous prototype for ‘kgd_gfx_aldebaran_clear_address_watch’ [-Wmissing-prototypes]
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c:782:10: warning: no previous prototype for ‘kgd_gfx_v11_clear_address_watch’ [-Wmissing-prototypes]

There are no callers from other files, so just mark them as 'static'.

Also fixes the following checks:

CHECK: Alignment should match open parenthesis +static uint32_t
kgd_gfx_aldebaran_clear_address_watch(struct amdgpu_device *adev,
uint32_t watch_id)

CHECK: Alignment should match open parenthesis +static uint32_t
kgd_gfx_v11_clear_address_watch(struct amdgpu_device *adev, uint32_t
watch_id)

Cc: Felix Kuehling <Felix.Kuehling@amd.com>
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: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>