SEOUL, SOUTH KOREA—Samsung Electronics Co. Ltd. will merge its mobile and consumer electronics divisions, the firm said on Tuesday, naming new co-chief executives in the biggest reshuffle since 2017 to simplify its structure and focus on the logic chip business. Two co-chief executives, instead of three, will lead the South Korean firm as it pivots on the two business pillars of chips and consumer devices, including smartphones, to help lead the next phase of growth and boost competitiveness. Samsung, whose Galaxy flagship brand helped it become the world’s biggest smartphone maker by volume, is seeking to revive slowing mobile growth, whose profit contribution shrank to 21 percent last quarter from nearly 70 percent at its peak in early 2010s. Instead, its component business, led by chips, has become the most profitable, helped by a boom in data storage and a recent shortage of global semiconductor supplies. The business generated nearly …