Complete the following C code that initializes Port B. You should make PB7 PBO outputs, and make PB4 PB1 inputs. All accesses to I/O registers must be friendly. In this question do not worry about AFSEL, PUR, PDR, AMSEL, or PCTL. Do not assume DIR, DEN or DATA registers have been cleared by the reset operation. #define GPIO_PORTB_DATA_R #define GPIO_PORTB_DIR_R #define GPIO_PORTB_DEN_R #define SYSCTL_RCGC2_R//Activate clock for Port B SYSCTL_RCGC2_R =//add code to allow time for clock to start//allow changes to PBO, 1, 4, 7 GPIO_PORT B_C R_R =//setup port B pin direction GPIO_PORTB_DIR_R =//enable data pins GPIO_PORTB DEN R =