mmc: core: Fix ambiguous TRIM and DISCARD arg

Clean up the MMC_TRIM_ARGS define that became ambiguous with DISCARD
introduction.  While at it, let's fix one usage where MMC_TRIM_ARGS falsely
included DISCARD too.

Fixes: b3bf9153 ("mmc: core: new discard feature support at eMMC v4.5")
Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/11376b5714964345908f3990f17e0701@hyperstone.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>