mmc: Fix HS200/HS400 capability check

HS200 and HS400 speeds can be enabled either with 1.2, or 1.8V signaling voltage.
Because of that we have four cabability flags: MMC_CAP_MMC_HS200_120,
MMC_CAP_MMC_HS200_180, MMC_CAP_MMC_HS400_120, MMC_CAP_MMC_HS400_180.

MMC logic only enables HS200/HS400 mode if both flags are set for the corresponding speed.
Fix that by being more permissive in host timing cap check.

Reviewed by: manu, mw
MFC after: 2 weeks
Obtained from: Semihalf
Sponsored by: Alstom Group
Differential revision: https://reviews.freebsd.org/D33130

(cherry picked from commit 8661e085fb953855dbc7059f21a64a05ae61b22c)