x86/entry: Zap the #VC entry user and kernel macros

x86/entry: Zap the #VC entry user and kernel macros

Drop the separate kernel and user macros in favor of calling a single #VC
C handler which multiplexes between the kernel and user #VC entry points
by looking at CS's RPL.

Zap unused DEFINE_IDTENTRY_VC while at it.

There should be no functionality change resulting from this - just code
simplification.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A. Dadhania <nikunj@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Nikunj A. Dadhania <nikunj@amd.com>
Link: https://patch.msgid.link/20260420164352.32129-1-bp@kernel.org