Description
GTC clock source is changed in the SPL boot flow to 200MHz, same is missing from boot app

Resolution

• Added the code to change the parent of GTC mux to MAIN_PLL0_HSDIV6_CLKOUT
• Set the default frequency of GTC (MAIN_PLL0_HSDIV6_CLKOUT) to 200 MHz

Root Cause
Boot app was not in alignment to SPL wrt GTC clock config, hence fixed the same