mmc: sdhci: Remove SDHCI_SDR104_NEEDS_TUNING

mmc: sdhci: Remove SDHCI_SDR104_NEEDS_TUNING

SDHCI_SDR104_NEEDS_TUNING was originally named SDHCI_HS200_NEEDS_TUNING
and was added in commit 55eb977a7086 ("mmc: host: Adds support for eMMC
4.5 HS200 mode").

That commit conflated SDHCI_SDR50_NEEDS_TUNING and SDHCI_HS200_NEEDS_TUNING
due to what appears to be misplaced parentheses.

Commit 2a613ad6fcde ("mmc: sdhci: fix caps2 for HS200") made HS200
configuration equivalent to SDR104 configuration, renaming
SDHCI_HS200_NEEDS_TUNING to SDHCI_SDR104_NEEDS_TUNING despite tuning for
HS200 now being non-optional.

The mix-up with SDHCI_SDR50_NEEDS_TUNING remained and became more obvious
after commit 0b9b9036d844 ("mmc: sdhci: clean up sdhci_execute_tuning()
decision") where the author noted the patch was "reflecting what the
original code was doing, it shows that it may not be what the author
actually intended."

The way the code is currently written, SDHCI_SDR104_NEEDS_TUNING
causes tuning to be done always for SDR50 mode if SDR104 mode is
also supported by the host controller.  That makes no sense because
we already have capabilities bit SDHCI_USE_SDR50_TUNING and
corresponding flag SDHCI_SDR50_NEEDS_TUNING for that purpose.

Given the dubious origins of SDHCI_SDR104_NEEDS_TUNING, it seems
reasonable to remove it.  The benefit being SDR50 mode will now not
un-nessessarily do tuning.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>