drm/amdgpu: Fix ISP hw init issue

ISP hw_init is not called with the recent changes related
to hw init levels. AMDGPU_INIT_LEVEL_DEFAULT is ignoring
the ISP IP block as AMDGPU_IP_BLK_MASK_ALL is derived using
incorrect max number of IP blocks.

Update AMDGPU_IP_BLK_MASK_ALL to use AMDGPU_MAX_IP_NUM
instead of (AMDGPU_MAX_IP_NUM - 1) to fix the issue.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Fixes: 14c11b71 ("drm/amdgpu: Add init levels")
Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>