HID: mcp2221: use mcp_i2c_smbus_read for block reads

HID: mcp2221: use mcp_i2c_smbus_read for block reads

Refactor mcp_smbus_xfer() to use the mcp_i2c_smbus_read() helper function
for I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_I2C_BLOCK_DATA read operations.

This replaces the manual setup of the receive buffer and explicit calls
to mcp_send_data_req_status(), making the code cleaner and more consistent
with other read paths in the driver.

Signed-off-by: Romain Sioen <romain.sioen@microchip.com>
Signed-off-by: Marius Cristea <marius.cristea@microchip.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>