mmc, sdhci, bcm-kona, LLVMLinux: Remove use of __initconst

The __initconst is in the wrong place, and when moved to the correct place
it uncovers an error where the variable is used by non-init data structures.

Instead merely make them const and put the const in the right spot.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>