x86/msr: Remove rdmsrl_on_cpu()

rdmsrl_on_cpu() has no users left. Delete it.

Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://patch.msgid.link/20260608051741.3207435-3-jgross@suse.com

arch/x86/include/asm/msr.h

@@ -329,7 +329,6 @@ static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
 /* Compatibility wrappers: */
 #define rdmsrl(msr, val) rdmsrq(msr, val)
 #define wrmsrl(msr, val) wrmsrq(msr, val)
-#define rdmsrl_on_cpu(cpu, msr, q) rdmsrq_on_cpu(cpu, msr, q)
 
 #endif /* __ASSEMBLER__ */
 #endif /* _ASM_X86_MSR_H */