Bluetooth: samples: Remove references to Kbuild-style building
Bluetooth: samples: Remove references to Kbuild-style building

Update the documentation for the Bluetooth samples not to refer to the
old style of building using make. Instead, simply refer to the general
instructions.

Signed-off-by: Johan Hedberg <628991c7b0a19c384f9b99c21ec330ce952bb838@intel.com>

GiulianoFranchetto/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,mbolivar/zephyr,explora26/zephyr,mbolivar/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,nashif/zephyr,finikorg/zephyr,mbolivar/zephyr,kraj/zephyr,galak/zephyr,galak/zephyr,kraj/zephyr,explora26/zephyr,aceofall/zephyr-iotos,kraj/zephyr,nashif/zephyr,ldts/zephyr,zephyriot/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,zephyriot/zephyr,ldts/zephyr,ldts/zephyr,Vudentz/zephyr,Vudentz/zephyr,punitvara/zephyr,galak/zephyr,Vudentz/zephyr,kraj/zephyr,Vudentz/zephyr,punitvara/zephyr,finikorg/zephyr,zephyriot/zephyr,zephyriot/zephyr,kraj/zephyr,finikorg/zephyr,galak/zephyr,aceofall/zephyr-iotos,aceofall/zephyr-iotos,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,mbolivar/zephyr,Vudentz/zephyr,galak/zephyr,nashif/zephyr,explora26/zephyr,explora26/zephyr,nashif/zephyr,punitvara/zephyr,ldts/zephyr,punitvara/zephyr,zephyriot/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,aceofall/zephyr-iotos,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr