ARM: omap2plus: select RESET_CONTROLLER

ARM: omap2plus: select RESET_CONTROLLER

With the new omap_prm driver added unconditionally, omap2 builds
fail when the reset controller subsystem is disabled:

drivers/soc/ti/omap_prm.o: In function `omap_prm_probe':
omap_prm.c:(.text+0x2d4): undefined reference to `devm_reset_controller_register'

Link: https://lore.kernel.org/r/20191216132132.3330811-1-arnd@arndb.de
Fixes: 3e99cb214f03 ("soc: ti: add initial PRM driver with reset control support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Olof Johansson <olof@lixom.net>