mmc: sdio: Check for CISTPL_VERS_1 buffer size

Before parsing CISTPL_VERS_1 structure check that its size is at least two
bytes to prevent buffer overflow.

Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20200727133837.19086-2-pali@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>