common: Kconfig: Fix CMD_BMP/BMP dependency

Using `default y` will not select BMP when CMD_BMP has been enabled, if
it was already configured.

By using `select`, if `CMD_BMP` is turned on, it will force the presence
of `BMP`.

Fixes: 072b0e16 ("common: Kconfig: Add BMP configs")
Signed-off-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Signed-off-by: Nikhil M Jain <n-jain1@ti.com>