mmc: sdhci: Allow caps[1] to be set via SDHCI_QUIRK_MISSING_CAPS

Currently only the capability_0 register can be set if
SDHCI_QUIRK_MISSING_CAPS is defined.  This is a problem when
the capability_1 register also needs changing.  Use the quirk
SDHCI_QUIRK_MISSING_CAPS to allow both registers to be set.

Redefining caps[1] is useful when the board design does not
support 1.8v vccq so UHS modes are not available.  The code that
calls sdhci_add_host can then detect this condition and adjust
the caps so the UHS mode will not be attempted on UHS cards.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>