removed -mexplicit-relocs cc flag and other options in the Makefile

Makefile

@@ -11,19 +11,19 @@ GCC_PREF=riscv32-unknown-elf-
 
 CC=$(GCC_PREF)gcc
 OBJDUMP=$(GCC_PREF)objdump
-CFLAGS=-I$(KLIBDIR) -O3 -MD -mcmodel=medany -mexplicit-relocs
+CFLAGS=-I$(KLIBDIR) -O3 -MD -mcmodel=medany
 KERNEL_CFLAGS=-nostdlib -T linker.ld
 ARCH = rv32im							# here you 
 
 ### Build configuration:
 
-# uncomment to build with only the rv32i standard
-CFLAGS += -D__risc_no_ext=1
-ARCH = rv32i
+# uncomment these to build with only the rv32i standard
+#CFLAGS += -D__risc_no_ext=1
+#ARCH = rv32i
 
 # configure if mtime is memory-mapped or inside a CSR:
 # replace 0xFF11FF22FF33 with the correct address
-CFLAGS += -DTIMECMP_IN_MEMORY=1 -DTIMECMP_MEM_ADDR=0xFF11FF22
+#CFLAGS += -DTIMECMP_IN_MEMORY=1 -DTIMECMP_MEM_ADDR=0xFF11FF22
 
 
 ### End configuration