drm/amdgpu: Fix potential integer overflow in scheduler mask calculations

The use of 1 << i in scheduler mask calculations can result in an
unintentional integer overflow due to the expression being
evaluated as a 32-bit signed integer.

This patch replaces 1 << i with 1ULL << i to ensure the operation
is performed as a 64-bit unsigned integer, preventing overflow

Discovered in coverity scan, CID 1636393, 1636175, 1636007, 1635853

Fixes: c5c63d9c ("drm/amdgpu: add amdgpu_gfx_sched_mask and amdgpu_compute_sched_mask debugfs")
Signed-off-by: Karol Przybylski <karprzy7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>