drm/amdgpu: Fix correct parameter desc for VCN idle check functions

drm/amdgpu: Fix correct parameter desc for VCN idle check functions

Fixes the kdoc for the following VCN idle check functions by updating
the parameter description from 'handle' to 'ip_block':

- vcn_v4_0_is_idle
- vcn_v4_0_3_is_idle
- vcn_v4_0_5_is_idle
- vcn_v5_0_1_is_idle

Fixes the below with gcc W=1:
drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c:935: warning: Function parameter or struct member 'ip_block' not described in 'vcn_v5_0_1_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c:935: warning: Excess function parameter 'handle' description in 'vcn_v5_0_1_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c:1972: warning: Function parameter or struct member 'ip_block' not described in 'vcn_v4_0_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c:1972: warning: Excess function parameter 'handle' description in 'vcn_v4_0_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c:1583: warning: Function parameter or struct member 'ip_block' not described in 'vcn_v4_0_3_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c:1583: warning: Excess function parameter 'handle' description in 'vcn_v4_0_3_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.c:1200: warning: Function parameter or struct member 'ip_block' not described in 'vcn_v5_0_0_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.c:1200: warning: Excess function parameter 'handle' description in 'vcn_v5_0_0_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c:1460: warning: Function parameter or struct member 'ip_block' not described in 'vcn_v4_0_5_is_idle'
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c:1460: warning: Excess function parameter 'handle' description in 'vcn_v4_0_5_is_idle'

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>