feat(clang): add support for riscv clang

This commit fixes relocation errors identified by the clang compiler and
marks the .gtl_page_tables section as no data otherwise there is a type
mismatch.

Signed-off-by: Bruno Sa <[email protected]>

Author: ninolomata

src/arch/riscv/arch.mk

@@ -44,3 +44,5 @@ arch-ldflags = -m $(ld_emulation)
 
 arch_mem_prot:=mmu
 PAGE_SIZE:=0x1000
+
+clang_arch_target:=riscv64

src/arch/riscv/sbi.c

@@ -222,7 +222,7 @@ static struct sbiret sbi_time_handler(unsigned long fid)
         csrs_sie_set(SIE_STIE);
     }
 
-    return (struct sbiret){ SBI_SUCCESS };
+    return (struct sbiret){ SBI_SUCCESS, 0 };
 }
 
 static void sbi_timer_irq_handler()
@@ -255,7 +255,7 @@ static struct sbiret sbi_ipi_handler(unsigned long fid)
         }
     }
 
-    return (struct sbiret){ SBI_SUCCESS };
+    return (struct sbiret){ SBI_SUCCESS, 0 };
 }
 
 static struct sbiret sbi_base_handler(unsigned long fid)