net: ti: icss-iep: Fix incorrect type for return value in extts_enable()

net: ti: icss-iep: Fix incorrect type for return value in extts_enable()

The variable ret in icss_iep_extts_enable() was incorrectly declared
as u32, while the function returns int and may return negative error
codes. This will cause sign extension issues and incorrect error
propagation. Update ret to be int to fix error handling.

This change corrects the declaration to avoid potential type mismatch.

Fixes: c1e0230eeaab ("net: ti: icss-iep: Add IEP driver")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250805142323.1949406-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>