drm/amdgpu/vce1: Fix VCE 1 firmware size and offsets

drm/amdgpu/vce1: Fix VCE 1 firmware size and offsets

The VCPU BO contains the actual FW at an offset, but
it was not calculated into the VCPU BO size.
Subtract this from the FW size to make sure there is
no out of bounds access.

Make sure the stack and data offsets are aligned to
the 32K TLB size.

Check that the FW microcode actually fits in the
space that is reserved for it.

Fixes: d4a640d4b9f3 ("drm/amdgpu/vce1: Implement VCE1 IP block (v2)")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>