ARM: efm32: switch to properly namespaced location property
Since commits:
281ec367bff4 (i2c: efm32: correct namespacing of location property)
d36f47fa8419 (serial: efm32: correct namespacing of location property)
10ed7e9847b6 (spi: efm32: correct namespacing of location property)
(contained in 3.17-rc1) all drivers support the correctly
namespaced location property. So use the better names now.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>