ARM: shmobile: Remove legacy EMEV2 SoC support

Get rid of legacy EMEV2 SoC code including the legacy clock
framework implementation. The multiplatform implementation
together with DT board support shall be used instead.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>