mailmap: Update email for Asahi Lina

Add an alias so I can more easily filter kernel-related emails.

Signed-off-by: Asahi Lina <lina+kernel@asahilina.net>
Link: https://lore.kernel.org/r/20250409-mailmap-lina-email-v1-1-265d05848ae3@asahilina.net
Signed-off-by: Sven Peter <sven@svenpeter.dev>

Author: Asahi Lina

.mailmap

@@ -102,6 +102,7 @@ Ard Biesheuvel <ardb@kernel.org> <ard.biesheuvel@linaro.org>
 Arnaud Patard <arnaud.patard@rtp-net.org>
 Arnd Bergmann <arnd@arndb.de>
 Arun Kumar Neelakantam <quic_aneela@quicinc.com> <aneela@codeaurora.org>
+Asahi Lina <lina+kernel@asahilina.net> <lina@asahilina.net>
 Ashok Raj Nagarajan <quic_arnagara@quicinc.com> <arnagara@codeaurora.org>
 Ashwin Chaugule <quic_ashwinc@quicinc.com> <ashwinc@codeaurora.org>
 Asutosh Das <quic_asutoshd@quicinc.com> <asutoshd@codeaurora.org>