dmaengine: imx-sdma: fix Excess kernel-doc warnings

dmaengine: imx-sdma: fix Excess kernel-doc warnings

Fix warnings of "Excess struct member" by removing those lines.
They are extraneous.

imx-sdma.c:467: warning: Excess struct member 'context_loaded' description in 'sdma_channel'
imx-sdma.c:467: warning: Excess struct member 'bd_pool' description in 'sdma_channel'
imx-sdma.c:500: warning: Excess struct member 'script_addrs' description in 'sdma_firmware_header'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20240119032832.4051-1-rdunlap@infradead.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>