dmaengine: ptdma: remove PT_OFFSET to avoid redefnition

Building on ARCH=um causes a "redefined" warning, so remove this
PT_OFFSET macro to avoid the warning.

drivers/dma/ptdma/ptdma.h:34: warning: "PT_OFFSET" redefined
34 | #define PT_OFFSET   0x0
|
In file included from ./arch/um/include/asm/thread_info.h:17,
from ./include/linux/thread_info.h:60,
from ./include/asm-generic/preempt.h:5,
from ./arch/um/include/generated/asm/preempt.h:1,
from ./include/linux/preempt.h:78,
from ./include/linux/spinlock.h:55,
from ./include/linux/wait.h:9,
from ./include/linux/wait_bit.h:8,
from ./include/linux/fs.h:6,
from ./include/linux/debugfs.h:15,
from drivers/dma/ptdma/ptdma-debugfs.c:12:
./arch/x86/um/shared/sysdep/ptrace_user.h:4: note: this is the location of the previous definition
4 | #define PT_OFFSET(r) ((r) * sizeof(long))

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 2a99524459ce ("dmaengine: ptdma: Initial driver for the AMD PTDMA")
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Link: https://lore.kernel.org/r/1630178908-54973-1-git-send-email-Sanju.Mehta@amd.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>