riscv: vmlinux.lds.S|vmlinux-xip.lds.S: remove `.fixup` section

These are no longer necessary now that we have a more standard extable
mechanism.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/kernel/vmlinux-xip.lds.S

@@ -45,7 +45,6 @@ SECTIONS
 		ENTRY_TEXT
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
-		*(.fixup)
 		_etext = .;
 	}
 	RO_DATA(L1_CACHE_BYTES)

arch/riscv/kernel/vmlinux.lds.S

@@ -48,7 +48,6 @@ SECTIONS
 		ENTRY_TEXT
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
-		*(.fixup)
 		_etext = .;
 	}