accel/qaic: Call drm_gem_create_mmap_offset() once for each BO

Every time QAIC_MMAP_BO ioctl is called for a BO,
drm_gem_create_mmap_offset() is called. Calling
drm_gem_create_mmap_offset() more then once for a BO seems redundant.

Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231208163457.1295993-6-quic_jhugo@quicinc.com