The flag, uniphier_emmc_block_addressing, is boolean logic, so
"bool' is more suitable.

uniphier_emmc_is_over_2gb() is not boolean - it returns 1 / 0
depending on the card density, or a negative value on failure.
Rename it to make it less confusing.

Change-Id: Ia646b1929147b644e0df07c46b54ab80548bc3bd
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>