drm/amdgpu: Fix parameter annotation in vcn_v5_0_0_is_idle

Update parameter description in the vcn_v5_0_0_is_idle function

Fixes the below with gcc W=1:
drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.c:1231: 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:1231: warning: Excess function parameter 'handle' description in 'vcn_v5_0_0_is_idle'

Cc: Christian König <[e-mail]>
Cc: Alex Deucher <[e-mail]>
Signed-off-by: Srinivasan Shanmugam <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.c

···
 /**
  * vcn_v5_0_0_is_idle - check VCN block is idle
  *
- * @handle: amdgpu_device pointer
+ * @ip_block: Pointer to the amdgpu_ip_block structure
  *
  * Check whether VCN block is idle
  */