powerpc32/chrp: fix section mismatch warning

This patch fixes a section mismatch warning

WARNING: vmlinux.o(.text+0x213b6): Section mismatch in reference from the function chrp_init_early() to the variable .init.data:boot_command_line
The function chrp_init_early() references
the variable __initdata boot_command_line.
This is often because chrp_init_early lacks a __initdata
annotation or the annotation of boot_command_line is wrong.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/chrp/setup.c

@@ -253,7 +253,7 @@ static void briq_restart(char *cmd)
  * But unfortunately, the firmware does not connect /chosen/{stdin,stdout}
  * the the built-in serial node. Instead, a /failsafe node is created.
  */
-static void chrp_init_early(void)
+static __init void chrp_init_early(void)
 {
 	struct device_node *node;
 	const char *property;