dmaengine: tegra-apb: remove unused tdma_read function

clang with W=1 reports
drivers/dma/tegra20-apb-dma.c:236:19: error: unused function
  'tdma_read' [-Werror,-Wunused-function]
static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
                  ^
This function is not used so remove it.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20230322121001.2569909-1-trix@redhat.com


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