mmc: cqhci: rename cqhci.c to cqhci-core.c

Rename cqhci.c to cqhci-core.c so that another source file can be added
to the cqhci module without having to rename the module.

Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-and-tested-by: Peng Zhou <peng.zhou@mediatek.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210126001456.382989-3-ebiggers@kernel.org


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