x86/microcode: Mark early_parse_cmdline() as __init

Fix section mismatch warning reported by modpost:

  .text:early_parse_cmdline() -> .init.data:boot_command_line

The function early_parse_cmdline() is only called during init and accesses
init data, so mark it __init to match its usage.

  [ bp: This happens only when the toolchain fails to inline the function and
    I haven't been able to reproduce it with any toolchain I'm using. Patch is
    obviously correct regardless. ]

Signed-off-by: Yu Peng <pengyu@kylinos.cn>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/all/20251030123757.1410904-1-pengyu@kylinos.cn

Author: Yu Peng

arch/x86/kernel/cpu/microcode/core.c

@@ -136,7 +136,7 @@ bool __init microcode_loader_disabled(void)
 	return dis_ucode_ldr;
 }
 
-static void early_parse_cmdline(void)
+static void __init early_parse_cmdline(void)
 {
 	char cmd_buf[64] = {};
 	char *s, *p = cmd_buf;