Remove keep keyword for .heap section

Author: linlingao

targets/TARGET_Cypress/TARGET_PSOC6/TARGET_CY8CKIT_062_WIFI_BT/device/TARGET_MCU_PSOC6_M4/TOOLCHAIN_GCC_ARM/cy8c6xx7_cm4_dual.ld

@@ -369,7 +369,7 @@ SECTIONS
         __HeapBase = .;
         __end__ = .;
         end = __end__;
-        KEEP(*(.heap*))
+        *(.heap*)
         . = ORIGIN(ram) + LENGTH(ram) - STACK_SIZE;
         __HeapLimit = .;
     } > ram