arm64: dts: qcom: sdm845-starqltechn: Fix i2c-gpio node name

arm64: dts: qcom: sdm845-starqltechn: Fix i2c-gpio node name

Fix the following DT checker warning:

$nodename:0: 'i2c21' does not match '^i2c(@.+|-[a-z0-9]+)?$'

Fixes: 3a4600448bef ("arm64: dts: qcom: sdm845-starqltechn: add display PMIC")
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251015-topic-starltechn_i2c_gpio-v1-1-6d303184ee87@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>