tools/nolibc: MIPS: drop manual stack pointer alignment

The stack pointer is already aligned by the kernel to a multiple of 16.
All modifications of the register have been removed from the entrypoint,
so the manual realignment is unnecessary.

Drop the manual alignment.

Suggested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.2502161523290.65342@angie.orcam.me.uk/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Link: https://lore.kernel.org/r/20250623-nolibc-mips-n32-v3-2-6ae2d89f4259@weissschuh.net

Author: t-8ch

tools/include/nolibc/arch-mips.h

@@ -186,8 +186,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __
 		".set push\n"
 		".set noreorder\n"
 		"move  $a0, $sp\n"       /* save stack pointer to $a0, as arg1 of _start_c */
-		"li    $t0, -8\n"
-		"and   $sp, $sp, $t0\n"  /* $sp must be 8-byte aligned                     */
 		"addiu $sp, $sp, -16\n"  /* the callee expects to save a0..a3 there        */
 		"lui $t9, %hi(_start_c)\n" /* ABI requires current function address in $t9 */
 		"ori $t9, %lo(_start_c)\n"