mmc: tmio: use mmc_can_gpio_cd() instead of checking TMIO_MMC_USE_GPIO_CD

mmc: tmio: use mmc_can_gpio_cd() instead of checking TMIO_MMC_USE_GPIO_CD

To use a GPIO line for card detection, TMIO_MMC_USE_GPIO_CD is set
by a legacy board (arch/sh/boards/mach-ecovec24).

For DT platforms, the "cd-gpios" property is a legitimate way for that
in case the IP-builtin card detection can not be used for some reason.
mmc_of_parse() calls mmc_gpiod_request_cd() to set up ctx->cd_gpio if
the "cd-gpios" property is specified.

To cater to both cases, mmc_can_gpio_cd() is a correct way to check
which card detection logic is used.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>